Thanks Niels!
Another behavior related to this:
In Clone Drawings - Locked or Not > Freely draw on Clones - Original will update mode
If you’re on a clone frame, pressing A causes it to create a new drawing.
Pressing ESC will clear the drawing (as mentioned above) so you have an empty drawing.
Pressing CTRL+Z will bring the drawing back, but it’s still a separate drawing instead of a clone.
Pressing CTRL+Z again will turn it back into a clone.
As a whole, kind of weird/can’t get used to it even after it happens several times.
I do appreciate being able to press * and have a new clean drawing despite being in this mode. So I don’t know how this scheme is related to that behavior.