I’m no sculpting savant, however, I do know the mask is not supposed to look like this. Problem is, I don’t know what’s going on or how to fix this issue. I have a suspicion the settings are the cause; I don’t normally use the other tools but if I had to take a guess they too have the same problem.
Here’s the file, if you need it.
Kat.blend (4.6 MB)