I’ve only had this problem recently and don’t know if it is a setting or not but recently after I’ve sculpted my model around (at the beginning I just use the grab tool) when I try to sculpt in some areas, the cursor shrinks and disappears. It might have something to do with the area I am working on (IE more and smaller polygons in the area) or it could just be a bug. I don’t remember having this problem before but it’s happening a lot now.
If I accidentally pressed something I shouldn’t have or changed an option I shouldn’t have, please let me know. Otherwise, this may be a bug.
Thanks in advance for any feedback.