Google Daydream build crashes after 15sec

I have a Google Daydream VR project and running it on Cardboard device.
I hadn’t changed anything in my computer configuration, but suddenly Android builds became buggy.
App starts normally - it asks to put device inside viewer, then my game works for nearly 15 seconds and crashes.
(Once in a blue moon it doesn’t crash though)

This might have started after I tried UE4.21 preview. But could 4.21 affect the behavior of 4.20?

UPDATE: app crashes even if you wait 15sec at ‘Place your phone into your Cardboard viewer’ screen.

Logcat contains following hints:

11-01 21:24:09.356 1312 1406 W WindowManager: App freeze timeout expired.

11-01 21:24:09.356 1312 1406 W WindowManager: Force clearing freeze: AppWindowToken{8f8200e token=Token{9e72609 ActivityRecord{f14eb10 u0 com.YourCompany.Memory/com.epicgames.ue4.GameActivity t1283}}}

11-01 21:24:11.315 1312 1348 W ActivityManager: Activity pause timeout for ActivityRecord{f14eb10 u0 com.YourCompany.Memory/com.epicgames.ue4.GameActivity t1283}

11-01 21:24:13.930 1312 1406 W WindowManager: Window freeze timeout expired.

11-01 21:24:13.931 1312 1406 W WindowManager: Force clearing orientation change: Window{29cd9c4 u0 com.YourCompany.Memory/com.epicgames.ue4.GameActivity}

11-01 21:24:13.946 1312 1325 D ConnectivityService: Returning BLOCKED NetworkInfo to uid=10135

11-01 21:24:13.950 1312 1638 I WindowManager: Screen frozen for +6s650ms due to Window{29cd9c4 u0 com.YourCompany.Memory/com.epicgames.ue4.GameActivity}

Build crashes on Android 9, Cardboard device (Xiaomi Redmi Note 5).
Build works on Android 8, Daydream device (Moto Z).