Musescore 4 quits unexpectedly

Working with a completely new installation I have been getting repeated unexpected termination of MU4 that seem to be triggered by repeated use of either the Escape key or Ctrl+Z .

On each occasion, I have been entering notes with a qwerty keyboard and mouse into a standard piano grand staff. I have no external music hardware attached. I'm simply using Windows 10's default internal GM Midi sounds.

I'm completely new to Musescore, trying to find my way around. Using these keys (Escape key or Ctrl+Z and backsapace) to go back or get out of whatever I got into is a fairly natural way to explore software I think.

I wasn't exactly putting Musescore through it's paces when the crashes happened and I'm using a fairly powerful PC that is super stable with other software...Dell Precision workstation with dual hexa core Xeon processors and 64 GB ram .

There was no error message prior to any of the terminations. The software just closed down.

Besides edge and chrome browsers and my internet security software, no other software was running.