Feed is downloaded instead of opened in Brief RSS reader (Firefox)

[slrslr]

When i click a RSS reader icon on the homepage https://lemmings.world/ where I am registered as a user,

then the URL is like https://lemmings.world/feeds/front/......long string here.....xml?sort=Active and it triggers a download of a file, not a page of my Firefox 140.0esr RSS reader "Brief 2.7.5". When I click a Briew icon in address bar, then I get correctly subscribed.

Other RSS feed like one linked from sub-lemmy https://lemmings.world/c/protonprivacy@lemmy.world is displayed properly in Brief.

When I compare subscribed feed URL with the URL of the on-page button, they are identical.

Please how this issue can be fixed?

[tanriol]

Thank you for reporting, will try to reproduce and fix if possible in a few days.

[slrslr]

Have you been able to reproduce it?

[slrslr]

will try to reproduce

several months passed 👀

[Nocoa]

I can confirm this is happening, but I can't pin down why. The returned Content-Type is "application/rss+xml" and the contents of the feed are valid (w3 validator). On a fresh visit to the lemmings.world homepage, the rss link opens in Brief fine, but on any subsequent visit to the page, the link instead tries to download the feed.

My guess would be this is some type of caching or header issue on lemmings.world, but I can't rule out a Brief issue.
Note: I can't reproduce this behavior on any other Lemmy instances either, just lemmings.world.