After a certain 6.x beta update a week or two back - I don't recall which, and I was expecting another update would fix it, but the original update appears to have caused an actual change in the order of the ENML tags for bulleted lists in the content of all? most? of my notes so the lists are all effectively upside down now.
It's not what I'd classify as serious, though when combined with the usual issues with bullets, which seem to be worse now, I'd definitely tag it with ^Major PITA
Apart from the usual issues with bullets, and the issue with numbered lists, I haven't seen a thread addressing this problem specifically. If there is one, then I'll happily delete this and move there instead.
EDIT: this comment / sub-thread addresses it insofar as to say if you took the risk of using beta versions then there's nothing that can be done and you're on your own. I'll leave this topic here as a top-level reference to that comment, and the follow-up.