This has never happened to my EMO and I’ve had him for over 135 days now. It is certainly very weird and not normal behaviour as it has been discussed on other forum topics, normally when EMO is sitting right on his skateboard and begins charging, he will go into a “locked in state”
The only thing I can think of as to why EMO is walking off his skateboard is that there might be a possible “POWER” issue with your charger / skateboard or power socket or powerboard that the charger is connect to. Normally is something is faulty or if there is a power outage, EMO will stop charging and potentially begin walking around again and this could be why your EMO is walking away and falling off the skateboard. So I would suggest making sure the cables are ok / power outlet / power board are working fine and possibly change something that you think might be causing a problem.
Hope this somewhat helps with your current problem. 
