I figured out how to trigger the bug...
Start in any Memory setting besides M1
Go into the menu (5-clicks)
Go to exit
Press the down button
It's now at M1
Hopefully this won't matter in a few days.
Thanks, I just tested and yes I see that with my 2.2. Didn't even need to press down, as soon as I exited the menu I saw it said M1 at the bottom where before I was in M4. But pressing down was further confirmation, showing me I was editing M1 now, displaying M1's figure on screen.
Oh well, it could be worse - at least it doesn't overwrite M1 with the content of M4 or anything like that (as my ipv4 does regularly.)