Well, it wouldn't be the first time an "upgrade" screwed up something that previously worked fine. But I upgraded a couple weeks ago. Apple insisted because of "serious security patches". And I didn't have have this issue until just a couple days ago. I don't hang out in the Q thread; was reading the Abe threads - and one particular thread at the other board.
So, I can buy that the OS version is part of the issue. I'm not totally convinced it's the whole answer, however, because I don't have the issue in other threads that are ALSO posting tweets. And all the other tweets in that other board's long thread don't have the same impact. Makes me wonder if there's some tag or something that comes WITH the problematic tweet that is causing the issue?