Rear hatch won't power closed?

[Red]

Our 2009 Murano has developed a new quirk. The power up/down rear door (hatch, whatever) will open withut any problem, but ignores any request from the fob or the button in the hatch to come back down and close.

I didn't see any mention of a reset, or a dedicated fuse for that motor(?) that closes it. Are these known for stripping a cam or something, so they open but don't close?

Or is this the kind of thing where it just needs a visit to the dealer so they can tear apart the rear trim and replace a whole motor assembly?

--Red