When I paint a mask using a certain sized brush I can control this fine. If I need to earse an area and chose a very small brush the first go gives me a much larger area, making it impossible to erase just a small area. If I then go back and paint in more mask, I get the same effect. I have checked the brush size each time but it seems no matter how small, a large area gets effected. It’s almost like auto mask is on, only I don’t think we have that feature. This is on my iPad Pro 12.9, running ISO10.3.3 or 11 B3. Very frustrating.