This is a new error message this morning when I tried to reply to a post (to an excellent long form dad joke, lol). I tried setting my language at Lemmy.world but got a warning that deselecting “undetermined” would mean that I can’t see “most content.” Which is weird because nothing in that pick list was selected in the first place and I haven’t yet had a problem posting/replying. This mobile app is stellar, by the way. :)
I had this weeks ago for some reason. Like you said, it’s definitely no a new issue.