LoopOut Causes Flash Frame

Steps to reproduce:
1. Create animated composition that you want to loop (in my case, used multiple masked versions of an AI file to create a strobing arrow animation)

2. Use the LoopOut expression after placing in another composition.

Result: On out point, frame fails to appear (sometimes randomly it will work, but fairly consistantly results in error)
Expected: LoopOut of composition not to blink out of existence on last frame.

***Does not occur if you render out the composition to file and replace, so it seems to only be with compositions. 

System info
    Application: After Effects (Beta) v18.3.0.11
    OS: Windows v10.0.18363, RAM: 31.73 GB, CPUs (logical): 16