Operating system: Windows7
Broken: version: 2.81 (sub 10), branch: master, commit date: 2019-09-12 09:34, hash: rB492a7998d508
Short description of error
If object origin not in center of the world (0,0,0), then rotating around 3d cursor going crazy.
Exact steps for others to reproduce the error
Move object origin from 0,0,0, set pivot point to 3d cursor, move 3d cursor where you want, go to sculpt mode, try rotate tool (or transform, etc). Then go to object mode, move origin to 0,0,0, go to sculpt mode try rotate again, now it works as expected.