Operating system: Windows-10-10.0.17134 64 Bits
Graphics card: GeForce GTX 560/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 391.35
Broken: version: 2.81 (sub 9), branch: master, commit date: 2019-09-09 17:22, hash: rB6be3348505ce
Broken shadows "traced path" glithc effect in the air in places where geomety have "complex area" (when you use shadows from Workbrench render and same in viewport).
Here is on video uou can see it. Sorry for broken english.
Exact steps for others to reproduce the error
Don't know how to reproduce it step by step, so I've put the file here: