Texture Painting: switches to FILL every time I do an UNDO

When Texture Painting, anyone else having an issue with the tool changing back to “Fill” after a CTRL+Z?

Like, if I draw 3 strokes, and hit ctrl+Z, the tool switches to FILL at the first ctrl+z and stays there.
EDIT: After re-boot, couldn’t replicate this specific problem. However, if you google “blender texture paint after undo” you’ll see that there have historically been a raft of problems with that sequence of actions. So, something ain’t right.