I think the changes to Auto pilot (which I really appreciate) may have had some unintended consequences on Ice Man. When commanded to a set altitude (eg when at 33k feet if you set absolute altitude to 35K feet) he will blow though and then over compensate and go down (e.g climb from 33K to 35K, keep going to 37K and then plummit to 33k again and keep bobbing up and down. In general ice man seems to be less responsive and accurate.
Baby sitting him and telling him to " hold current" seems to somewhat help the problem but he will still drift of altitude a lot. sometimes he will settle down into an altitude but then randomly depart from it, or start rolling
For a dedicated RIO like me this is making things pretty hard but I understand he is a work in progress.