I have been trying out Pro Motion with an XP-Pen Artist 22E display tablet and found what seems to be a weird bug.
I’ve recorded it in action in the video below, however the issue seems to be that drawing with the pen causes all strokes to be drawn with the background colour instead of the foreground colour. This continues even if I switch back to mouse.
What I see is that the pressure range definition is reset to be “undefined”. The light blue bar defines at which position the stroke starts with the smallest pressure and ends with the highest pressure:
Strange enough, this was also reset on my system, but stupidly I corrected this before starting to test. At the moment I don’t know why that happened and have to further analyze.
Also I (maybe due to my correction) I could not duplicate the button color mismatch problem. Will continue testing. Maybe you can define the pressure range on your system by just clicking and dragging into the black frame to make the light blue bar appear.