Note: Reproduction steps may vary or be completely random

Steps to reproduce:
1. Download project from OC (link in last edit)
2. Open project
3. Enter play mode
-- Notice the number on the top left of the screen, which shows the number of visible spheres queried from culling group.
4. Try to drag scene window near game window (This step may not reproduce the issue. Look at attached GIFs or try other possible combinations)

Results: the number on the top left of the screen, which shows the number of visible spheres queried from culling group, displays 0.

Not reproducible when Occlusion>Visualization window is opened.

Reproduced with: 5.4.0b25, 5.3.5p7, 5.2.4f1