Reproduction steps:
1. Open project in "Test.zip"
2. Build and install the application to an iOS device
3. Shut down the application on the iOS completely
4. Connect your iOS device to a monitor using an adapter (e.g. lightning to HDMI/DP/USB-C)
5. Open the Application (it will be named "Test")
6. Inspect both screens (device and connected)
7. Disconnect and re-connect the display adapter
8. Inspect both screens

Expected behavior: connected display is the same as in step 6
Actual behavior: connected display goes black (in 2021.2.0a2 the application crashes upon launch, read note below)

Reproducible with: 2019.4.14f1, 2020.1.13f1, 2020.2.0b9, 2021.1.0a5, 2021.2.0a1
Could not test with 2018.4.29f1 screen didn't go black but the project looked different (parts of it were missing in build), so I did not count this as a valid test

Reproducible with:
VLNQA00310 iPad Pro 12.9 1st gen (iOS 13.4.1)

Not reproduced with:
VLNQA00096, Samsung Galaxy S8 (SM-G950F), Android 8.0.0, CPU: Exynos 9 Octa 8895, GPU: Mali-G71

Note: the application started crashing on launch in 2021.2.0a2 (full trace in edits):
Few lines from trace:
UnityFramework was compiled with optimization - stepping may behave oddly; variables may not be available.
* thread #1, queue = 'com.apple.main-thread', stop reason = signal SIGABRT
frame #0: 0x00000001b824cd88 libsystem_kernel.dylib`__pthread_kill + 8
...
* frame #4: 0x0000000102e5a02c UnityFramework`-[UnityAppController application:didFinishLaunchingWithOptions:](self=0x000000028398c480, _cmd=<unavailable>, application=<unavailable>, launchOptions=<unavailable>) at UnityAppController.mm:341:9 [opt]