AR camera screen is black

Hello, I'm using AR Foundation [4.0.12] in Unity [2020.3.0f1] We are developing an AR app for iPad. As for the contents of the application, the scene on the standby screen is displayed first, and when you press the start button, the scene changes and the AR camera starts. If you leave it for a certain period of time without touching the screen in the AR scene, it will switch to the standby screen. The app worked fine on the test iPad. However, when I put it in the actual iPad pro 10.5-inch, There is no problem if you press the start button immediately after startup to move to the AR scene, If you leave it untouched for a long time (about 10 hours or more) on the standby screen, When I switch to the AR scene, the screen goes black and AR does not work. The UI on the screen remains displayed, and if you leave it for a certain period of time, it will return to the standby screen. In that state, it will not return unless you restart the application once. I'm checking the profiler of Unity, but I don't understand the cause. Do you have any idea what the cause is? Thank you.

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Development environment Unity: 2020.3.0f1 ARFoundation: 4.0.12 Xcode: 12.5.1

Actual machine: iPad pro 10.5 inch iOS: iOS15.1

Hey, same problem here, I have a really hard time to reproduce this bug. I'm using Unity and our Museum IPad App uses the same pattern with an Idlescreen. I'm deactivating the ARSession Object when the Idlescreen is active but on some devices some times, the ARSession is not waking back up (or some subsystem? Couldnt reproduce so no chance to debug). Did you found anything useful or a solution to this problem? Is it maybe even a system bug and an IOS Update helps?

AR camera screen is black
 
 
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