Rotate tool OpenGL enabled document error RETURNS! (new iMac M1)

I can't believe this. I'm in the middle of a project, using my new iMac 24" M1, and all is well. I use the rotation tool quite a lot, due to some tricky paint work - it's really an essential tool for my work. Unfortunately, this morning, I can no longer use the rotate tool - I get the dreaded 'Could not complete your request because it only works with OpenGL enabled document windows' error. 

This happens from time to time, even on my new computer, but it usually clears up if I shut down and restart Photoshop. Not this time. I can no longer rotate any of my projects. I've gone into advanced graphics processor settings, and Use OpenCL is checked off (not OpenGL) - see the screen cap. I'm at a loss - none of the methods for fixing this that people have posted in the past have worked. Oddly, I had my file open and was rotating it without any issues, then a couple of hours later, that function was no longer available. How could that happen? Help.