In reply to MarkR:
I’ve ridden a Haibike xduro (with the SES so maybe different to yours) for well over 3.5k miles and only once had the chain come off the chain ring and jam. Cause - put down to the clutch on the derailleur having been in the off position by mistake coupled to the rough terrain or something that caused the chain to “bounce”.
Is your clutch on (assuming your spec has one)?
My bike has mostly been ridden off road and has had some hard rough rides so it’s not a normal problem in my experience with the Haibike design with the SES system if it is set up properly.
Sounds like your bike has not been set up correctly (esp if it is changing cogs on its own) or has some fault/damage? Are all the chain ring teeth ok or could the chain have been damaged from shipping to cause lift?
A remote possibility is I know if the chain ring outer guard is not properly tightened (I’ve seen this on a new ebike) this allows the chain ring to move and if too slack can wobble and this could “help” to lift the chain up on top of the chain ring teeth. Probably more so if the derailleur is not setup right.
See what the shop says and take it from there.
Post edited at 21:13