I have seen the same behaviour on my mobile browser. Desktop seems to not have rhe issue. Error when upvotiing, fixed by a page reload followed by an immediate upvote.
Same here. I've just noticed this over the last 24 to 48 hours. And it seems to be worse on computer. Right now I've been browsing with Firefox on Android and it seems to be doing fine.
I started this way and now am getting all kinds of 50x errors doing various actions. I imagine something is being changed (it seemed to go to hell just before midnight UTC), but I can't find any status page or the like. I can't sort this forum by new (some 50x error), most threads work intermittently, and I don't see anything in kbinDevlog that seems related.