The chain on my FS has started flicking over the chain stay and wedging between derailleur cage and stay thus stopping the bike dead. Luckily it seems to only happen on the granny ring so not going very fast when this happens. The chain although part worn isn’t that bad, the derailleur looks straight and so does the granny ring. So any ideas would be very welcome, my only thought is that the granny is more worn than I think and this is a weird form of chain suck.
PS no obvious signs of bent chain side plates either.

Are you pedalling or free wheeling when this happens ?

Might be a jamming free hub, get off bike and try pedaling the hub backwards, if it is the hub it can also snap the chain, as i found out last week,an over the bars flying lesson

Pedalling,and it will pedal backwards easily so I am assuming the freewheel is ok