After swapping the AOSEM for SR2 M2 UL earlier this week, and learning that it was not the culprit (alog 39263), I replaced the M2 stage Quadrapus cable.  JeffK checked it on the fly while I was in the chamber and verified that it seems to have fixed the issue.  Cable that was removed was D1000234-v4-00-903.  New cable is D1000234-v4-00-S1106125.