Comment, flag, and delete causes a jump to the top of the page. You also can't press the inbox or achievements button. This applies to all Stack Exchange and meta sites.
I have cleared the cache. It only works on up-to-date browsers (so it is a duplicate question in that regard, but the fact it is not working on older Chrome versions has not been addressed), but I will not be updating from my may 2018 Chrome desktop and Android versions to the new versions due to horrible UI changes and functionality loss.
Why has it suddenly (as of some time in December, I think 10th December 2021) stopped working on those versions?