Now you have me worried, I think this might be related to my trackball mod pushing the ball slightly too high as now I’m seeing it too. Do you have one the newest reforms that has the ball bearings in the trackball?
EDIT: Just tested my own here, I wet the center of a microfibre cloth with some screen cleaning fluid and put that right over the trackball. Closing down the lid showed the liquid transferred to the screen. So at very least the ball is very close, and given there’s some vertical play this could be related.
I’m going to revert back to the old stock trackball and see if this persists. I thought though I kept the height the same.