Which version of myFocuserPro2 firmware do you run?
I've now updated to 328, and it works well with simulators but I have not yet been able to test it under the stars.
So, I updated the firmware on myfocuser2 to 328. I'm running the latest stable release of KStars and Indi as per Nou's scripts... and everything appears to be well behaved again!
I tried 10 focus procedures with the 7 different filters mounted on my systems, i,e., 70 focusing operations, and the focusing procedure completed all the time without issues. The setting was linear1pass with Classic "steps" (I found that actually CFZ and the other "step" modes gave me inferior results... ), circle area of 80%, both fitting optimization on (I really like it), and AF Overscan set to 0 as also the Backlash in and out compensation in the driver set to 0.
It's true that the "strangeness" has the very bad habit of appearing suddenly out of the blue, however I would say that it is again solved by the last iteration of the MyFoc2 firmware, at least I hope so.