Sensorless mode may indeed trigger the cut outs if the hub gets jammed up with no pedals to start, but this I am not entirely sure of. I would advise keeping the current down to the motor until you get this sorted. Any overload will make the
BMS kick off the controller. This will be indicated to loss of throttle lights.
Some of the solder points maybe poor inside this controller and this could create a low drop on fet side of the shunt. Again we are not sure as the controller is over complicated IMO with all theses weird beeps that really seem to mean nothing if the controller hasnt been soldered properly to begin with.
Is there some beeps that indicate crappy controller soldering? Otherwise the beeps are presumptuous to the fact that there is a normal malfunction such as hall sensor failure. I would rather a controller that doesnt fail over a controller that always fails and has beeps to tell you something as obvious as hall failure or fet failure as usually the solution to all and any other problems is to check your connections or get a new controller. So why do we need beeps to tell us the same stuff.
100v fets and 100v caps for the regen controller would be a start, IMHO the regen voltage between the motor and the shunt can exceed the capacitor rating making it fuse. On a full charged pack there is only about 7v difference between a full pack and the 63v cap. This is designed to fail IMO. THAT(S WHY THEY ARE FAILING!
My suggestions are always ignored so we still see much more failures.
You may need to get an external controller with a reputable track record. Yes something with at least 100v caps.
I get the feeling the hub isnt giving you anymore power. Maybe something inside the hub has shaken lose or a poor solder point has failed during your off road use.
If GM doesnt make good on support youre are going to have to deal with this problem yourself.
Meaning open your hub, remove, the internal controller, run hall wires and phase wires out side to an external controller, with the right gear the motor should be a pearl,