diff --git a/plugins/module_utils/infrahub_utils.py b/plugins/module_utils/infrahub_utils.py
index 392a173..d5b2a2a 100644
--- a/plugins/module_utils/infrahub_utils.py
+++ b/plugins/module_utils/infrahub_utils.py
@@ -1298,8 +1298,11 @@ def _get_object(
             if not node_id and not node_hfid:
                 return None
 
+            include = [key for key in data if key not in ("id", "hfid")] or None
             try:
-                node = self.client.fetch_single_node(kind=kind, id=node_id, hfid=node_hfid, raise_when_missing=False)
+                node = self.client.fetch_single_node(
+                    kind=kind, id=node_id, hfid=node_hfid, include=include, raise_when_missing=False
+                )
             except Exception as exc:
                 self._handle_errors(f"An error occurred while retrieving {kind} {data} due to {exc}")
 
diff --git a/tests/unit/plugins/module_utils/test_node.py b/tests/unit/plugins/module_utils/test_node.py
index eef8de5..8a3db04 100644
--- a/tests/unit/plugins/module_utils/test_node.py
+++ b/tests/unit/plugins/module_utils/test_node.py
@@ -540,6 +540,54 @@ def test_update_real_checksum_mismatch_triggers_upload(self, tmp_path):
         existing_node.save.assert_called_once()
 
 
+# ---------------------------------------------------------------------------
+# Regression: _get_object must pass user data keys as include on fetch.
+# Without include, cardinality-MANY relationships stay uninitialized on the
+# fetched node and are missing from the "before" diff snapshot, so idempotent
+# re-runs report changed: true (fixed in 6f1315e, lost in 0142ad6).
+# ---------------------------------------------------------------------------
+
+
+class TestGetObjectIncludesUserKeys:
+    def test_fetch_includes_user_data_keys(self):
+        """_get_object passes user field names as include, excluding id/hfid."""
+        mock_client = make_mock_client(existing_node=make_mock_node())
+        mock_module = make_mock_module()
+
+        node_module = NodeModule(module=mock_module, client=mock_client)
+        data = {
+            "id": "uuid-1234",
+            "name": {"value": "tag1"},
+            "description": {"value": "managed by ansible"},
+            "related_tags": [{"id": "uuid-5678"}],
+        }
+        node_module._get_object(schema=MagicMock(), kind="BuiltinTag", data=data)
+
+        mock_client.fetch_single_node.assert_called_once_with(
+            kind="BuiltinTag",
+            id="uuid-1234",
+            hfid=None,
+            include=["name", "description", "related_tags"],
+            raise_when_missing=False,
+        )
+
+    def test_fetch_identifier_only_defaults_include_to_none(self):
+        """Identifier-only data (e.g. state: absent) keeps default fetch behavior."""
+        mock_client = make_mock_client(existing_node=make_mock_node())
+        mock_module = make_mock_module()
+
+        node_module = NodeModule(module=mock_module, client=mock_client)
+        node_module._get_object(schema=MagicMock(), kind="BuiltinTag", data={"id": "uuid-1234"})
+
+        mock_client.fetch_single_node.assert_called_once_with(
+            kind="BuiltinTag",
+            id="uuid-1234",
+            hfid=None,
+            include=None,
+            raise_when_missing=False,
+        )
+
+
 # ---------------------------------------------------------------------------
 # Schema-based version gating (CoreFileObject inherit_from validation)
 # ---------------------------------------------------------------------------