Stays on OEM screen

[itvitacredit]

1. Start Engine
2. Reverse (it turn back camera on)
3. Show OEM navigation.
   After 2. it should switch back to android.

2-3 Mins and it switchs to android...
PS, Android boot up 20-40 secs

and second problem
If I put reverse after driving... (5-10 mins), in reverse no parking sound