So, here is the bluetooh fix!
Bluetooth (and apps using it) will degrade their playback performance if battery saver option is enabled.
This is due to an aggressive battery policy made by google, as this problem is not only present in blackview smartphones but also in google's ones!
You must disable the battery optimization option for the bluetooth services and for every app that will use bluetooth to transmit data (spotify, music player, and so on...) After that, your bluetooth performance will be perfect.
1) Go to settings -> Battery
2) Tap on the "3 dots" in the upper right corner of the app
3) Tap on "Battery optimization"
4) Select "All apps" from the drop down menu
5) Tap on the desired app and select "Don't optimize"
As i wrote before, you have to disable battery optimization for every bluetooth service (Bluetooth MIDI service, BT Tool, Bluetooth sharing) and for every app that will use bluetooth to transmit data (your music player, Call manager, telephone dialer app and so on). You will find everything in the "All apps" list in the Battery optimization settings.
Example of disabled optimization in attachment.
- Screenshot_20171129-200611.png (158.52 KiB) Viewed 2378 times
- Screenshot_20171129-200604.png (164.25 KiB) Viewed 2378 times