Operating system: Windows-7-6.1.7601-SP1 64 Bits
Graphics card: GeForce GTX 660 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 456.71
Broken: version: 2.93.0 Alpha, branch: master, commit date: 2021-02-02 23:17, hash: rB2ce1400297d7
Worked: (newest version of Blender that worked as expected)
Short description of error
After few strokes and remeshes this n-gon gone away.
I did not encounter this ever before.