Reproduction steps:
1. Open the attached "987107.zip" project.
2. Build it to iOS using IL2CPP.
3. Click the play symbol.
4. Click on the black target marker.
- The arrangement of objects changes.
5. Click on the black target marker again.
- The game will no longer progress.
- Xcode console will start to loop:

...
UnityEngine.DebugLogHandler:LogFormat(LogType, Object, String, Object[])
UnityEngine.Logger:Log(LogType, Object)
UnityEngine.Debug:Log(Object)
Main:Changeposcitizen()
Main:Update()

(Filename: /Users/builduser/buildslave/unity/build/artifacts/generated/common/runtime/DebugBindings.gen.cpp Line: 51)
...

Reproduced with:
- IL2CPP

Not reproducible with:
- Mono (Android, iOS)
or
- Editor

Notes:
- Works fine using mono on Android
- Crashes using mono on iOS (May not be related: crash log attached)