System Information
Operating system: Linux-5.7.10-201.fc32.x86_64-x86_64-with-fedora-32-Thirty_Two 64 Bits
Graphics card: GeForce GTX 970M/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 440.100

Blender Version
Broken: version: 2.91.0 Alpha, branch: master, commit date: 2020-08-27 05:33, hash: rB54b47da56596
Caused by rBa9f2ebb21508: Cleanup: DRW: Use GPUState instead of raw opengl calls

Short description of error
Workbench shadows are not showing

Exact steps for others to reproduce the error
From the default startup:

• make sure you are in Solid shading mode
• add a plane beneath the Cube, scale it by 5
• in the Shading popover, enable shadows
• notice all geometry getting slightly darker, but shadow is actually not showing