I have been flying AC2.9 on my QAV500G for a while. It works great. I now upgraded to AC3.1 and suddenly I get very high frequency oscillations in roll (low amplitude). If I reduce my P-gains drastically the oscillations disappears, but then the QAV gets sloppy.
Is there an explanation on why this could happen when moving from 2.9 to 3.1? I have performed all calibration steps except for the ESCs.