| Just to clarify, what really made the trick was the fact that I downloaded the firmware from 7.0 Nougat to Marshmallows 6.0.1. In the APN settings, I also added the APN type to: "default,supl,internet,mms,VoLTE,OTA". Also, APN protocol to "IPv4/IPv6". The phone started making quick phone calls again.
PLEASE CLICK ON THE THANKS BUTTON IF THIS POST WAS HELPFULL |