Authenticator login with Firefox is broken

Sorry if I’m posting this in the wrong category, but there does not seem to be a category for the web site as a whole.

Logging in with Firefox is currently not possible. When prompted for the authenticator the browser is simply redirected back to the login form. This appears to be due to the authenticator page trying to load a URL that gives a 404 status.

The URL in question is an icon (for Android?):


This is the relative URL as I am not allowed to include the full URL on the forum.

If I block this URL in my browser, i.e. right-click and “Block URL” in the Network tab of the Developer Tools, the login works fine.

I assume there is functionality on the authenticator page to redirect back to the login form if it hits a 404. I did not encounter this issue with any chromium based browsers, as it appears the URL is not accessed there.

My user agent if that is of any relevance: Mozilla/5.0 (X11; Linux x86_64; rv:124.0) Gecko/20100101 Firefox/124.0

I’m having the same symptoms on my Firefox 124.0.2 (64-Bit) Windows System as of today. After briefly showing the authenticator request (which also gets pinged to the app and can be approved with no actual result) I get redirected back to the login.

Works in Chromium based browser though.

Updated to 125.0.1
Issue persists