This was initially seen on my ST W project, but I managed to reproduce it in a smaller project too, but I really needed to generate a lot of sprites in the see the visual glitches.
Only happens when the Camera is set to Perspective. Orthographic works fine. Sometimes i see the same artefacts in the scene view as well.
Also, I could not repro this on my GTX 1070.

Repro:
- download project
- run SampleScene and use WASD to move the little character around
- notice sometimes blinds or dark patches appear instead of the trees