Reproduction steps:
1. Download and open the repro project form the attached link
2. Open and play the "CorridorDemo" scene (Assets\Scenes)
3. Check in the profiler, that ever 2 seconds, when FakeCamera calls to Render function, it shows a performance spike on Culling call

Note:
- When on "FakeCamera" Culling Mask is set only to "water" layer there aren't any spikes. Spikes are about from 5 ms to 18 ms.
- This culling spike problem relates to realtime reflection probes as well. Performance spikes are higher about 10 ms when realtime reflection probe (set to render all elements) is rendered faster than every 0.5 s.