Subpresentations are flashing when there is a rectangle behind them

Test environment:
MacBook Pro
OS X 10.13.6

Test steps:
1. Open the attached project. There are three layers: “Layer” with rectangle which acts as a background, “Left” with a subpresentation which includes cube and no background, and “Right” with a subpresentation which includes cone and no background.
2. Look the project in the editor view for 10-20 seconds
-> Cube and cone (both added as subpresentations) are “flashing” i.e. disappearing and appearing on the canvas.