Operating system: Windows-10-10.0.18362 64 Bits
Graphics card: GeForce GTX 980/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 436.30
Broken: version: 2.81 (sub 13), branch: master, commit date: 2019-10-04 22:33, hash: rBab519b91b2c4
Short description of error
Preserve Sharp creates triangle holes in the mesh.
Exact steps for others to reproduce the error
Just take the standard cube and go into Sculpt Mode. Use the settings that are shown in the screenshot. There should be two triangle holes appearing on two sides of the cube.