This issue comes from the fact that even though the domain is now changed to x.com, it still tries to load content from twitter.com which Firefox thinks is social media tracking because it's coming from a different domain than the one you're on.
It's a hilarious and dumb oversight with this change.
Looks like Elon finally forces x down everyone's throat and every twitter.com link redirects to x.com. (Funny enough I tried Firefox Nighty and there is no redirect so maybe this is random based on UA)
Also I'm not 100% sure but enhanced tracking protection probably breaks x.com because there are still API calls to twitter.com under the hood, since those are different domains it just gets blocked. Solution is either twitter fixes their shitty code or Mozilla adds exception.