**System Information**
Operating system: Linux-4.15.0-153-generic-x86_64-with-glibc2.27 64 Bits
Graphics card: Mesa DRI Intel(R) HD Graphics 5500 (BDW GT2) Intel Open Source Technology Center 4.6 (Core Profile) Mesa 20.0.8
**Blender Version**
Broken: version: 3.0.0 Alpha, branch: master, commit date: 2021-08-14 20:50, hash: `rBd5261e973b56` and also 2.93.3 Release Candidate, branch: master, commit date: 2021-08-12 15:05, hash: 1eeae9be1531
**Short description of error**
I have a simple object with 4 plane and three modifiers a subdivisions surfaces a two solidify applied each one to a group of vertex but the green is OK but the red have a strange behavior I attached the file to inspect this bug, but is easily reproducible.
**Exact steps for others to reproduce the error**
If you create an object with two vertexs groups and each one you assign a solidify applied only to a group the object react differently and one is wrong.
{F10284807}
{F10284803}
{F10284805}