This bug appears on iOS 15. It is not present on newer iOS versions, however a bunch of older Apple devices that are still widely used cannot be updated and your game might not run on those.
Sometimes, the exported game doesn't start after it's been fully loaded. If you have a custom loader layout enabled the 'On loader layout complete' trigger will fire, but the game never actually goes to the next layout. The bug occurs regardless of what loader style you use, but never happens if you run the game from the remote preview.
FIX: Go to the project settings and set 'Max spritesheet size' to 4096.
Posting on the forum so more people see how to fix this. I will submit the bug report later as I don't have any apple devices on me right now (luckily).
anyway, think differently folks and don't do drugs