It worked. When creating a new profile it is fixed. I don’t know what was broken before and I guess it would be a pain to figure out so I’ll just go with a new profile. Thanks a lot.

I’ve already enabled all settings that gives LibreWolf the ability to save cookies. My assumption is, since I can’t find any cookies at all in the Discord web app that are related to authentication, that they are storing it in the localStorage instead. There are a few “token” values, although I don’t know which of the different variables exactly is responsible for what. The localStorage also doesn’t seem to clear when reloading though, so I’m still stuck on figuring out what’s the problem. The more I think about it, I assume it might be better to just ask discord support about it.