Ok, it didn't take long to figure out it was a language issue. I have now selected every possible language and the problem is gone, it took me months to fix it, lol. I do, however, see a problem with this language implementation

The same has been happening to me. Seems like accessing anything from lemmy.world is broken. I can open any post with hundreds of comments only to see a single one. The same happens with the sync app, as well as in a browser, though only at lemmy.world.