diff --git a/test/common/debugger.js b/test/common/debugger.js
index dbaa62e71d3f..73a34a767763 100644
--- a/test/common/debugger.js
+++ b/test/common/debugger.js
@@ -27,6 +27,8 @@ function startCLI(args, flags = [], spawnOpts = {}, opts = { randomPort: true })
     ...args,
   ], spawnOpts);
 
+  const closed = new Promise((resolve) => child.once('close', resolve));
+
   const outputBuffer = [];
   function bufferOutput(chunk) {
     if (this === child.stderr) {
@@ -180,10 +182,8 @@ function startCLI(args, flags = [], spawnOpts = {}, opts = { randomPort: true })
     },
 
     quit() {
-      return new Promise((resolve) => {
-        child.stdin.end();
-        child.on('close', resolve);
-      });
+      child.stdin.end();
+      return closed;
     },
   };
 }
diff --git a/test/es-module/es-module.status b/test/es-module/es-module.status
index 376b9cdeb07b..2e18fb7c96a1 100644
--- a/test/es-module/es-module.status
+++ b/test/es-module/es-module.status
@@ -6,10 +6,6 @@ prefix es-module
 
 [true] # This section applies to all platforms
 
-[$system==linux || $system==freebsd]
-# https://github.com/nodejs/node/issues/47836
-test-esm-loader-http-imports: PASS,FLAKY
-
 [$arch==arm || $arch==arm64]
 # https://github.com/nodejs/node/issues/47297
 test-wasm-web-api: SKIP
diff --git a/test/es-module/test-esm-loader-http-imports.mjs b/test/es-module/test-esm-loader-http-imports.mjs
index 07e84eddd861..96bfffe5b13f 100644
--- a/test/es-module/test-esm-loader-http-imports.mjs
+++ b/test/es-module/test-esm-loader-http-imports.mjs
@@ -34,7 +34,9 @@ const requestListener = ({ url }, rsp) => {
     .end();
 };
 
-const server = http.createServer(requestListener);
+// Leave closing idle connections to the client, so that the loader never
+// reuses a keep-alive socket the server has just closed.
+const server = http.createServer({ keepAliveTimeout: 0 }, requestListener);
 
 await promisify(server.listen.bind(server))({
   host: '127.0.0.1',
diff --git a/test/fixtures/debugger/alive.js b/test/fixtures/debugger/alive.js
index c8ad157b452d..0b06798508a7 100644
--- a/test/fixtures/debugger/alive.js
+++ b/test/fixtures/debugger/alive.js
@@ -3,3 +3,5 @@ function heartbeat() {
   ++x;
 }
 setInterval(heartbeat, 50);
+
+if (process.send) process.send('ready');
diff --git a/test/parallel/parallel.status b/test/parallel/parallel.status
index b260a86594c1..be53eda583b8 100644
--- a/test/parallel/parallel.status
+++ b/test/parallel/parallel.status
@@ -20,8 +20,6 @@ test-fs-read-stream-concurrent-reads: PASS, FLAKY
 test-snapshot-incompatible: SKIP
 
 [$system==win32]
-# https://github.com/nodejs/node/issues/59090
-test-inspector-network-fetch: PASS, FLAKY
 # https://github.com/nodejs/node/issues/59636
 test-fs-cp-sync-symlink-points-to-dest-error: SKIP
 test-fs-cp-async-symlink-points-to-dest: SKIP
@@ -36,9 +34,6 @@ test-performance-function: PASS, FLAKY
 test-esm-loader-hooks-inspect-wait: PASS, FLAKY
 
 [$system==macos]
-# https://github.com/nodejs/node/issues/42741
-test-http-server-headers-timeout-keepalive: PASS,FLAKY
-test-http-server-request-timeout-keepalive: PASS,FLAKY
 # https://github.com/nodejs/node/issues/60050
 test-cluster-dgram-1: SKIP
 
@@ -141,10 +136,6 @@ test-tls-set-default-ca-certificates-append-fetch: SKIP
 test-tls-set-default-ca-certificates-reset-fetch: SKIP
 test-inspector-invalid-protocol: SKIP
 
-[$asan==on]
-# https://github.com/nodejs/node/issues/39655
-test-cluster-primary-error: PASS, FLAKY
-
 [$arch==loong64]
 # https://github.com/nodejs/node/issues/51662
 test-http-correct-hostname: SKIP
@@ -152,8 +143,3 @@ test-http-correct-hostname: SKIP
 [$arch==riscv64]
 # Snapshot test works in some environments but not others for now on RISC-V
 test-snapshot-reproducible: PASS, FLAKY
-# styletext ones are failing in jenkins but pass standalone so something
-# odd is happening to the ttys when run via java. tty issue
-# https://github.com/nodejs/build/issues/4099#issuecomment-5070947806
-test-util-styletext: PASS, FLAKY
-test-util-styletext-hex: PASS, FLAKY
diff --git a/test/parallel/test-cluster-primary-error.js b/test/parallel/test-cluster-primary-error.js
index 232de51f29fb..f9ebdc4c85d1 100644
--- a/test/parallel/test-cluster-primary-error.js
+++ b/test/parallel/test-cluster-primary-error.js
@@ -88,12 +88,24 @@ if (cluster.isWorker) {
     // Check that the cluster died accidentally (non-zero exit code)
     assert.strictEqual(code, 1);
 
+    // Probe with signal 0. common.isAlive() sends SIGCONT, which discards the
+    // pending SIGSTOP that LeakSanitizer's exit-time stop-the-world waits for
+    // under ASan on Linux, leaving the exiting worker hung forever.
+    const isAlive = (pid) => {
+      try {
+        return process.kill(pid, 0);
+      } catch (err) {
+        if (err.code !== 'ESRCH') throw err;
+        return false;
+      }
+    };
+
     // XXX(addaleax): The fact that this uses raw PIDs makes the test inherently
     // flaky – another process might end up being started right after the
     // workers finished and receive the same PID.
     const pollWorkers = () => {
       // When primary is dead all workers should be dead too
-      if (workers.some((pid) => common.isAlive(pid))) {
+      if (workers.some(isAlive)) {
         setTimeout(pollWorkers, 50);
       }
     };
diff --git a/test/parallel/test-http-server-headers-timeout-keepalive.js b/test/parallel/test-http-server-headers-timeout-keepalive.js
index 493c730cb7a9..1a9d060c9ff3 100644
--- a/test/parallel/test-http-server-headers-timeout-keepalive.js
+++ b/test/parallel/test-http-server-headers-timeout-keepalive.js
@@ -70,7 +70,7 @@ server.listen(0, common.mustCall(() => {
         performRequestWithDelay(
           client,
           headersTimeout / 5,
-          headersTimeout,
+          headersTimeout * 2,
           true
         );
       }, defer).unref();
diff --git a/test/parallel/test-inspector-close-terminate-connections.js b/test/parallel/test-inspector-close-terminate-connections.js
index ab18ad277dbb..e055044506b6 100644
--- a/test/parallel/test-inspector-close-terminate-connections.js
+++ b/test/parallel/test-inspector-close-terminate-connections.js
@@ -18,9 +18,9 @@ async function test() {
   const instance = new NodeInstance(['--inspect-brk=0'], script);
   const session = await instance.connectInspectorSession();
 
-  // Enable Runtime domain and wait for an event to confirm the session is live.
-  await session.send({ method: 'Runtime.enable' });
-  await session.waitForNotification('Runtime.executionContextCreated');
+  // Wait until the child is ready to receive the resume command.
+  await session.send({ method: 'NodeRuntime.enable' });
+  await session.waitForNotification('NodeRuntime.waitingForDebugger');
 
   // Resume execution so the script calls inspector.close().
   await session.send({ method: 'Runtime.runIfWaitingForDebugger' });
diff --git a/test/parallel/test-inspector-network-fetch.js b/test/parallel/test-inspector-network-fetch.js
index 790446c84bfb..a637d3495466 100644
--- a/test/parallel/test-inspector-network-fetch.js
+++ b/test/parallel/test-inspector-network-fetch.js
@@ -12,9 +12,10 @@ const http = require('node:http');
 const https = require('node:https');
 const inspector = require('node:inspector/promises');
 
-// Disable certificate validation for the global fetch.
+// Keep local requests independent of proxy settings and allow the test certificate.
 const undici = require('internal/deps/undici/undici');
 undici.setGlobalDispatcher(new undici.EnvHttpProxyAgent({
+  noProxy: '*',
   connect: {
     rejectUnauthorized: false,
   },
@@ -205,8 +206,10 @@ const testNetworkInspection = async () => {
   session.removeAllListeners();
 };
 
-httpServer.listen(0, () => {
-  httpsServer.listen(0, async () => {
+// Listen on the address the requests go to, so that a socket another process
+// binds to 127.0.0.1 on the same port cannot take the connections over.
+httpServer.listen(0, '127.0.0.1', () => {
+  httpsServer.listen(0, '127.0.0.1', async () => {
     try {
       await session.post('Network.enable');
       await testNetworkInspection();
diff --git a/test/parallel/test-util-styletext-hex.js b/test/parallel/test-util-styletext-hex.js
index f12c35a780d6..9677217bd331 100644
--- a/test/parallel/test-util-styletext-hex.js
+++ b/test/parallel/test-util-styletext-hex.js
@@ -213,8 +213,10 @@ describe('util.styleText hex color support', () => {
       for (const testCase of testCases) {
         it(`should respect ${testCase.description}`, () => {
           writeStream.isTTY = testCase.isTTY;
+          // Do not inherit color-related variables (TERM, CI, NO_COLOR, ...)
+          // from the environment the test happens to run in.
           process.env = {
-            ...originalEnv,
+            TERM: 'xterm-256color',
             ...testCase.env,
           };
           const output = util.styleText('#ffcc00', 'test', { stream: writeStream });
diff --git a/test/parallel/test-util-styletext.js b/test/parallel/test-util-styletext.js
index 3db01bec1c3a..ba81aae06d83 100644
--- a/test/parallel/test-util-styletext.js
+++ b/test/parallel/test-util-styletext.js
@@ -203,9 +203,11 @@ if (fd !== -1) {
     { isTTY: true, env: { FORCE_COLOR: '1', NO_COLOR: '1', NODE_DISABLE_COLORS: '1' }, expected: styled },
   ].forEach((testCase) => {
     writeStream.isTTY = testCase.isTTY;
+    // Do not inherit color-related variables (TERM, CI, NO_COLOR, ...) from
+    // the environment the test happens to run in.
     process.env = {
-      ...process.env,
-      ...testCase.env
+      TERM: 'xterm-256color',
+      ...testCase.env,
     };
     {
       const output = util.styleText('red', 'test', { stream: writeStream });
diff --git a/test/sequential/sequential.status b/test/sequential/sequential.status
index 4111eb2b8ecf..f155b6747333 100644
--- a/test/sequential/sequential.status
+++ b/test/sequential/sequential.status
@@ -11,18 +11,11 @@ test-cpu-prof-dir-worker: PASS, FLAKY
 test-http2-large-file: PASS, FLAKY
 
 [$system==win32]
-# https://github.com/nodejs/node/issues/63212#issuecomment-5423558796
-test-debugger-pid: PASS, FLAKY
 
 [$system==linux]
-# https://github.com/nodejs/node/issues/54817
-test-http-server-request-timeouts-mixed: PASS, FLAKY
 
 [$system==macos]
 
-# https://github.com/nodejs/node/issues/43465
-test-http-server-request-timeouts-mixed: PASS, FLAKY
-
 [$system==solaris] # Also applies to SmartOS
 test-worker-prof: PASS, FLAKY
 
diff --git a/test/sequential/test-debugger-pid.js b/test/sequential/test-debugger-pid.js
index 97218b796cae..f05f968e4601 100644
--- a/test/sequential/test-debugger-pid.js
+++ b/test/sequential/test-debugger-pid.js
@@ -8,11 +8,15 @@ const startCLI = require('../common/debugger');
 
 const assert = require('assert');
 const { spawn } = require('child_process');
+const { once } = require('events');
 
 const script = fixtures.path('debugger', 'alive.js');
 
 (async () => {
-  const target = spawn(process.execPath, [script]);
+  const target = spawn(process.execPath, [script], {
+    stdio: ['ignore', 'pipe', 'pipe', 'ipc'],
+  });
+  await once(target, 'message');
   const cli = startCLI(['-p', `${target.pid}`], [], {}, { randomPort: false });
 
   try {
@@ -25,7 +29,8 @@ const script = fixtures.path('debugger', 'alive.js');
       /> 3 {3}\+\+x;/,
       'marks the 3rd line');
   } finally {
-    await cli.quit();
+    const targetClosed = once(target, 'close');
     target.kill();
+    await Promise.all([cli.quit(), targetClosed]);
   }
 })().then(common.mustCall());
diff --git a/test/sequential/test-debugger-quit-after-exit.js b/test/sequential/test-debugger-quit-after-exit.js
new file mode 100644
index 000000000000..7e02175435bd
--- /dev/null
+++ b/test/sequential/test-debugger-quit-after-exit.js
@@ -0,0 +1,12 @@
+'use strict';
+const common = require('../common');
+common.skipIfInspectorDisabled();
+
+const assert = require('assert');
+const startCLI = require('../common/debugger');
+
+(async () => {
+  const cli = startCLI(['--help'], [], {}, { randomPort: false });
+  await assert.rejects(cli.waitForPrompt(), /Child exited while waiting/);
+  await cli.quit();
+})().then(common.mustCall());
diff --git a/test/sequential/test-http-server-request-timeouts-mixed.js b/test/sequential/test-http-server-request-timeouts-mixed.js
index 034aa3630bbf..8e79cf6c9316 100644
--- a/test/sequential/test-http-server-request-timeouts-mixed.js
+++ b/test/sequential/test-http-server-request-timeouts-mixed.js
@@ -2,6 +2,7 @@
 
 const common = require('../common');
 const assert = require('assert');
+const { once } = require('events');
 const { createServer } = require('http');
 const { connect } = require('net');
 
@@ -70,7 +71,7 @@ server.listen(0, common.mustCall(() => {
   request1.client.write(requestBodyPart1);
 
   // After a little while send two new requests
-  setTimeout(() => {
+  setTimeout(common.mustCall(() => {
     request2 = createClient(server);
     request3 = createClient(server);
 
@@ -79,7 +80,17 @@ server.listen(0, common.mustCall(() => {
 
     // Send the third request and stop in the middle of the headers
     request3.client.write(requestBodyPart1);
-  }, headersTimeout * 0.2);
+
+    request2.client.on('end', common.mustCall(() => {
+      // The second request times out due to headersTimeout, so after the first
+      // request has been completed and before the fourth request's body is sent
+      assert(request1.completed);
+      assert(!request4.completed);
+
+      assert(request1.response.startsWith(responseOk));
+      assert(request2.response.startsWith(responseTimeout)); // It is expired due to headersTimeout
+    }));
+  }), headersTimeout * 0.2);
 
   // After another little while send the last two new requests
   setTimeout(() => {
@@ -103,31 +114,23 @@ server.listen(0, common.mustCall(() => {
   }, headersTimeout * 0.8);
 
   setTimeout(common.mustCall(() => {
-    // After the first timeout, the first request should have been completed and second timedout
-    assert(request1.completed);
-    assert(request2.completed);
+    // After the first timeout, the requests with completed headers should still be pending
     assert(!request3.completed);
     assert(!request4.completed);
     assert(!request5.completed);
 
-    assert(request1.response.startsWith(responseOk));
-    assert(request2.response.startsWith(responseTimeout)); // It is expired due to headersTimeout
+    const pending = [request3, request4, request5];
+    Promise.all(pending.map(({ client }) => once(client, 'end'))).then(common.mustCall(() => {
+      // All request should be completed now, either with 200 or 408
+      assert(request3.response.startsWith(responseTimeout)); // It is expired due to requestTimeout
+      assert(request4.response.startsWith(responseOk));
+      assert(request5.response.startsWith(responseTimeout)); // It is expired due to requestTimeout
+      server.close();
+    }));
   }), headersTimeout * 1.4);
 
   setTimeout(() => {
     // Complete the body for the fourth request
     request4.client.write(requestBodyPart3);
   }, headersTimeout * 1.5);
-
-  setTimeout(common.mustCall(() => {
-    // All request should be completed now, either with 200 or 408
-    assert(request3.completed);
-    assert(request4.completed);
-    assert(request5.completed);
-
-    assert(request3.response.startsWith(responseTimeout)); // It is expired due to requestTimeout
-    assert(request4.response.startsWith(responseOk));
-    assert(request5.response.startsWith(responseTimeout)); // It is expired due to requestTimeout
-    server.close();
-  }), headersTimeout * 3 + connectionsCheckingInterval);
 }));
diff --git a/test/test-runner/test-run-watch-cwd-isolation-none.mjs b/test/test-runner/test-run-watch-cwd-isolation-none.mjs
index bbb1a141a4b4..c3d32883781a 100644
--- a/test/test-runner/test-run-watch-cwd-isolation-none.mjs
+++ b/test/test-runner/test-run-watch-cwd-isolation-none.mjs
@@ -1,14 +1,20 @@
 // Test run({ watch: true, cwd, isolation: 'none' }) runs with different cwd while in watch mode and isolation none
 import * as common from '../common/index.mjs';
 import * as fixtures from '../common/fixtures.mjs';
+import { readdir, readFile } from 'node:fs/promises';
 import { run } from 'node:test';
 import { skipIfNoWatch } from '../common/watch.js';
 
 skipIfNoWatch();
 
+// Read the fixtures before watching them. On Windows, their first read can
+// update access times and trigger a restart without changing their contents.
+const cwd = fixtures.path('test-runner-watch');
+await Promise.all((await readdir(cwd)).map((file) => readFile(fixtures.path('test-runner-watch', file))));
+
 const controller = new AbortController();
 const stream = run({
-  cwd: fixtures.path('test-runner-watch'),
+  cwd,
   watch: true,
   signal: controller.signal,
   isolation: 'none',
diff --git a/test/test-runner/test-runner.status b/test/test-runner/test-runner.status
index 7ad99e20a87e..65ae96eb9e37 100644
--- a/test/test-runner/test-runner.status
+++ b/test/test-runner/test-runner.status
@@ -5,8 +5,3 @@ prefix test-runner
 # sample-test                        : PASS,FLAKY
 
 [true] # This section applies to all platforms
-
-[$system==win32]
-# https://github.com/nodejs/node/issues/66056
-test-run-watch-cwd-isolation-none: PASS, FLAKY
-test-run-watch-cwd-isolation-none-argv: PASS, FLAKY