Video attached.  In the video I'm just cranking it backwards to easily reproduce the issue.  Seems like the tensioner is jamming it somehow.  This started happening on my wife's bike a few days back after she hit a pot hole in the road.  Eventually the chain popped off.

We don't really know much about bikes, so I thought I'd reach out to here to see if this is something obvious before we took it to a shop.

It wasn't letting me attach the video for some reason, so here is a link:  https://streamable.com/a88zvh