My 2017 Bolt w/37000 miles resides in a detached garage (30'X30' pole barn) that has a 60-amp subpanel fed from the 200-amp service in the adjacent building. Subpanel is connected to its own ground rod, sunk into wet soil. The subpanel feeds a Clipper Creek HCS-40 that I upgraded to when I bought the Bolt in December of 2017. Previously, I had 2 different Leafs, charged with a Schneider EVSE. The 2 doors have Liftmaster operators that were supplied and installed by the builder; I wired them to power when I wired the building.
The Bolt was alone in the garage during the "incident". I came out from the house and looked to the garage to see both doors open. This was about 9:00 AM; the Bolt is set to finish charging at 10:00 AM, so charging was in progress. These operators are modern, using the current technology in their radio units. I'm kind of guessing that the charging process emitted RFI that caused the operators to open the doors.
Liftmaster tech support hasn't been of any help, at least so far.
It appears as though I should shut off the circuit breaker if I leave town...