Operating system: Windows-10-10.0.18362-SP0 64 Bits
Graphics card: 67EF:CF ATI Technologies Inc. 4.5.13559 Core Profile Context 26.20.12028.2
Broken: version: 2.83.5, branch: master, commit date: 2020-08-19 06:07, hash: rBc2b144df395f
Worked: (newest version of Blender that worked as expected)
Short description of error
It looks like the material applied to the wrong polygons.
Exact steps for others to reproduce the error
See the blend file below.