How to reproduce:
1. Open the attached project
2. Open the "SampleScene" from the Assets folder
3. Make sure that the Scene window isn't visible
4. Press play

Expected result: the top two cubes and the bottom two cubes are in-synch with each other
Actual result: two cubes on the right side are one frame behind the two left cubes

Reproducible with package versions: 7.1.7 (2020.2.0a5), 7.1.8 (2020.2.0a5)
Not reproducible with package versions: 7.2.0 (2020.2.0a5), 7.2.1 (2020.2.0a5), 7.3.1 (2019.3.8f1), 8.0.1 (2020.1.0b3)
Could not test with package version: 4.10.0 (2018.4.20f1, no BeginCameraRendering or BeginFrameRendering methods in the RenderPipeline class)

Notes:
-This isn't reproducible if the Scene window is visible at the same time as the Game window
-This bug is reproducible most of the time, very rarely the cube pairs are in-synch without the Scene window being open