I got a Xiaomi Mi Note Pro with MIUI v8 and Android 7.0, when i use the Lock App service on any app i want to protect, that app becomes only a black screen. This happen since MIUI 7 and android 5.5.
In the past i have sended this "bug" to Avast support but the problem is still present. I don't know if this happens on other devices but its quite annoying because this is a PRO feature but i cant use it.
Is there a way to fix this? And how have you done it?