update:
so the first replacement (used/tested) unit that i procured above was sent back due to possible internal issues (ac button light) ... but that replacement unit still exhibited the passenger side door actuator issues (even after replacing actuator).
a 2nd unit was received and with the same actuator in, i have not yet experienced the issue yet over the past week. so quite possible it was the hvac unit the entire time, but wouldn't make sense why the 1st replacement also imposed the same issue. time will tell.
