I really wish folks would attempt to give a detailed diagnosis, as you have done.
Just realized what is the problem: upgrade to Nest Plus version 1.4.0 from 1.3.3. They have, as you said, changed the key mapping as a result of adding new context menu commands. Since I was working on some things in Nest2Ami, had not bothered to upgrade to the new Plus version so far and did not notice the issue. Thanks again.
Will provide an updated version 0.85 by tomorrow. For those who need it, drop a PM.