@AK1122 and @spring Was your problem solved? One of my boards is in warranty now for this issue, but so far they apparently could not find anything wrong :-( I had both the motor taking off after 2 foot dismount from a dead stop and the more worrisome board taking off while you are simply riding straight on smooth pavement and in control. This board was practically new straight out of the box when I discovered it didn't behave like my other one.
I'm happy to report the 2 problems with one of my boards seem to have been solved :-) FM report says they replaced the sensor foot pad and recalibrated. So far so good.