Firefox 110.0 upgrade, now interface getting stuck with loading placeholders

I have upgraded Firefox to 110.0 on MacOS, and now our installation of EE will only load a few pages before every page gets stuck loading and only placeholders are shown. Clearing storage and restarting lets me load 2 or 3 more times, but then back to the same only placeholders. This is not the case in Safari.

Errors in console:

Uncaught (in promise) TypeError: NetworkError when attempting to fetch resource. 
The resource at “...” preloaded with link preload was not used within a few seconds. Make sure all attributes of the preload tag are set correctly.

Any ideas what may be going on?

Talking with a coworker, this may be related to access via Azure App Proxy. I don’t know if something has changed so the Firefox upgrade may be purely coincidental. Really frustrating issue, but I’m not at all convinced it is a Gitlab issue or a Firefox issue.