I believe I may have seen something like this before, reaching out to the community on ideas of what could be up.
So the first time something like this happened everything got fried. This time around I have managed to not fry everything. Basicly what happens is I turn the board on and pull the gt2b trigger, motor just cogs. With the board on its back the wheel just goes forward a bit then lurches back, then forward, etc etc.
When I go to turn off using the cutoff switch it still keeps twitching so i have to unplug the battery. Took everything apart, plugged the battery in and noticed a spark. With a cutoff switch there shouldnt be a spark so this arose some worries. The motor off of its belt and trigger pulled, she stutters but spins up.
Not sure what just happened but putting everything back together now. Going to space things out some more in hopes that the cutoff switch just got hot from a heavy ride. Last time this happened to me it was a heavy ride that I had just got done with when this happened. May not be a problem with the ESC but the cutoff switch itself… hhhmmmmmmmm