without changing any others settings but toggle on/off on only one setting, I have done some trials and it shows that whenever I switched the 'use 5G standalone networks' to ON, my voice incoming & outgoing calls will failed. I can successfully making and receiving calls again after I switched the 'use 5G standalone networks' to OFF again. 

if I'm not wrong, Currently there are 2 type of 5Gs which is 5G-NSA(4G base) & 5G-SA , my trials suggest that 5G-SA network itself at current stage UNABLE to support the basic voice phone calls. 

Question :

Any settings or updates to enable Samsung A53-5G to be able to auto switched to VoLTE for voice calls when the 'use 5G standalone networks' to ON? so that users can enjoy the 5G ultra speed promised and still able to receive or make important voice calls.

Thanks Samsung Team.