The code is : *#9646633#

I have the same problem. The OTG stop After minutes even then I have not unplug the device (a USB realtek audio jack 3.5 converter). The OTG intelligent fonction must be updated. You need to open the OTG, Settings-Smart Assist-Go to open OTG I have do that. But normally OTG stop after 15 minutes af...

To use properly the Qi charger you have to place the dock at the two lower-thirds of the phone.
Centre of dock must be in front of E of Blackview.

Hope that's help you.

To Switch under macro mode you have to click on the square image on top right of thé screen under camera app.
After you click on Macro Lens

Last security patch is outrages (december 5 2019).
You have to follow Android security updates more quickly.

I have the same problem.
The OTG stop After minutes even then I have not unplug the device (a USB realtek audio jack 3.5 converter).
The OTG intelligent fonction must be updated.