Just an update to anyone following this thread.

I've been working with Steve Brady at FocusMax to validate this problem and after several tests he was able to validate and identify the problem.

This is a problem that was introduced in FocusMax V4.1.0.62 and may affect anyone trying to use Filter Offsets in ACP. Basically, the focuser will not move to the expected offset value.

It specifically happens if:

Temp Comp method = none in Temperature Compensation Window of FMx AND when FMx is running under automation.

To test if this problem affects your set up, you can use the script previously mentioned in this thread and run it from APC to see if your focuser moves.

Steve has solved this problem and will release a fix shortly, but for now if this issue affects you may want to switch to per filter focusing.