Autofocus on a C11" SCT Using the Celestron Motor Focuser

I’ve been using the SharpCap to get good focus with the Celestron motor focuser. When trying SGP (after reading the manual and several online videos), I am finding keeping in focus to be very difficult. I actually focused first with SC and then switched to SGP and ran autofocus and it worked. After several frames it ran again per my settings and it did not work. It shifted way out of focus. I realize the Celestron motor focuser is not ideal in that the primary mirror can shift vs. using the Moonlight autofocuser in which the primary gets locked down. So, that insane problem. The other is when I was close to focus, noted my current position and HFR, and then started to back the focuser out to see the HFR increase. Well, it did both, increase and decrease (bouncing around) despite keep moving it out. It did not seem to just be a matter of settling down or backlash but not sure. Any suggestions on getting this right or is this tool on a SCT where the primary mirror moves just a finicky process?

One would have to see an auto focus graph, and your settings in Auto Focus Options.

Besides please answer the following questions:

Did you adjust the focusser backlash sufficiently?
Are you using NB filters? In this case indicate the exposure times for AF runs per filter.

Bernd