What I can tell you is very simple: the autopilot works, but there are some bugs that can be ignored by anyone who knows what to do with an autopilot. FD, VS, Pitch Selector, NAV, VNAV, HDG, HDG, ALT, SPEED (selector), CRS, BANK, APPR, all those functions are ok. No autotrottle, neither FADEC.
In addition, it is an excellent bizjet, one of the best in Carenado.
You doing everything right, you'll feel likely in Greg's P1D videos. LoL
Cheers,