I think I’ve figured this out:
for some stupid reason Aileron were set to “normal” in 3.9.2 while they were set to “reversed” in 3.9.1. Strangely, elevator “reverse” setting was not touched. This for sure shouldn’t have happened.
if your plane randomly switches modes, it means there is an issue with your RC calibration, make sure you have setup your flight mode switches correctly on your radio.