Could try disabling VoLTE/4g calling, and seeing if Wifi calling works then. I know some Android's prefer to use 4g calling over Wifi calling if both are enabled. Where i live i barely get any 4g so before i got an iPhone i had to have 4g calling disabled to get anywhere.
Switching the phone to Airplane mode turns off the GSM/3G/4G radio bits so that’ll check whether WiFi Calling works or not.
This issue is related to BT. Got confirmation. Apparently I am not the only one with non-working WiFi calling.
Trust me, I've tried all the above things and more before I contacted BT.
You probably know this already but dial *#*#4636#*#* to see if VoLTE and VoWiFi are provisioned on the SIM.
SIM is fine and everything is working if I put it in another phone. A different SIM is working on well my phone. What is not working is the BT SIM on my Note 20.
What an interesting sequence of events.
Decided to get a new phone. Got Samsung S21 Ultra 5G. Same problem. Wifi calling broken!!!
Samsung Korea got in touch with BT network Engineers with a solution and we've got if fixed!!! Permanent fix should be released with a new firmware upgrade.
Very good collaboration with the BT Engineer!
I had the same issue with my Ultra 5G. Weird occurrence, I let the phone die, and after charging and turning it, it said new network features, and to restart. After that Wi-Fi Calling, and VoLTE appeared, and worked! Also, have you installed the software update?
my problem had nothing to do with that. There is an issue with the phone firmware that has been confirmed by Samsung Korea software team 😉 Trust me, I have tried everything. The good thing is we have found the issue and temporarily fixed it while we wait for the new software.
I have same issue as yourself. What is the way around this.
You need to add a custom APN as per below instruction:
Settings - Connections - Mobile Networks - Access Point Names - Add -
APN type: ims (Delete "default" that was written at the beginning)
APN protocol: IPv6)