[OS X Emacs] sometimes i can't type

[Tom Van Vleck]

At least once a day, I will be editing away in Aquamacs,
and go to use the delete key, and nothing will happen.
When it gets into this state, left-arrow doesn't seem to
work either.  I bash at the keyboard a little and it gets
unstuck. I think when it is stuck, delete left-arrow won't 
work either. Might be that right-arrow unsticks it.

This is Aquamacs 3.6, build 20G165.	
I have observed this on a 10-year-old MacBook Pro
running Big Sur, and an m2 Air on Ventura.

I have looked in the *messages buffer after this happens
and the last thing in the last 2 occurrences was "Mark set"
but that could be a coincidence.

Anybody else see this ever?