Have been trying to figure this issue out for the past week:
After every flight it’s curious that I can’t disarm the copter in Loiter Mode - whenever I do the CSC to disarm, the motors throttle up, as if it were still trying to maneuver.
I usually have to switch to Stabilize, which audibly brings down the throttle a lot more, and then the CSC command usually works, but not always. Also tried recalibrating the remote to no avail.
I have the same issue though switching to stabilise always lets me disarm. Funnily though, I built a tricopter for a friend using an apm 2.5 with AC3.2 and we can disarm his in PosHold everytime.
Only thing I did differently was covered up the unused pins and any other holes in the case with insulation tape. I “think” wind is getting though my casing and disturbing the barometer just enough to stop the landing detector from realising it has actually landed, so rather than disarming it thinks your commanding a hard yaw.
Ok this will be because of the slightly more strict landing detector. If you’re in AltHold, Land or PosHold you should be able to get it to disarm by just leaving it a few seconds longer with the throttle at minimum. Also if your copter is slightly underpowered (i.e. hovers at above 60% throttle) setting the THR_MID higher will help.