Ordering cards no longer works with undo
I'm describing what I have experienced with specifically recross the paths, but I believe it impacts other cards as well, mostly scry. However it does not impact augur of bolas.
If you can order a set of cards, undo no longer undoes the last card placed in that order.
I know it happened sometime during the point where recross was broken, but I don't know when it happened for other cards with similar issues