I have problems receiving voice calls on my OPPO A5 (2020)

Press the phone icon.

Press the menu icon.

Press Settings.

Press Carrier Call Settings.

Press Call Forwarding.

Press the required SIM.

Press the required divert type.

901

901

Key in 901 and press On.

Press the Home key to return to the home screen.

Press the phone icon.

Press the menu icon.

Press Settings.

Press Carrier Call Settings.

Press Call Forwarding.

Press the required SIM.

Press the required divert type.

Press Off.

Press the Home key to return to the home screen.

Press On/Off.

Simultaneously, press and hold the Top volume key and keep them both pressed until your phone restarts.

Press the phone icon.

Press the menu icon.

Press Settings.

Press Carrier Call Settings.

Press Call Barring.

Press the required SIM.

Press the indicator next to the required barring type to turn the function on or off.

Key in your barring password.

Press the Home key to return to the home screen.