I took delivery of a new S20 FE on Friday last week - since then I've not been able to get WiFi calling working.
I am with Asda Mobile and they have tried a number of things, however the WiFi calling options will not appear on the handset. However, on completing some further testing, beginning to wonder if it could be the handset?
Take a Vodaphone SIM that is working with WiFi calling in another handset. Installed that into the S20 FE - no WiFi calling options. Completed a couple of restarts, no options appear.
Took Asda mobile SIM and plugged that into a Samsung A12. The A12 received two CS messages from Asda Mobile - installed these, WiFi calling options available.
Removed Asda SIM, reinserted into the S20 FE - still no options available.
Removed all SIM's from the S20 FE and completed a full factory reset. Went through the basic setup and then reinstalled the Asda SIM - still no WiFi calling options.
The only odd thing is that when I inserted the Asda Mobile SIM into the A12, within seconds there were two CS messages from Asda Mobile, which I installed.
When I reinserted the Asda Mobile SIM into my S20 FE after the factory reset I didn't receive any CS messages, nothing at all.
However - the fact I can take this Asda SIM and insert it into another handset and get the WiFi calling issues and I take a SIM from an old A20e (with WiFi calling working) and insert and still don't have any options. Is this looking like a potential handset issue?
I don't unfortunately have an EE SIM I can try - I know EE's network seems to work differently with WiFi calling and stuff "just works" as opposed to Vodafone/Asda where features need to be activated etc.
There isn't a way I can force the CS messages to be downloaded to a phone I'm assuming?
Yer - they do - https://mobile.asda.com/wifi-calling
As I mentioned, if I move my Asda SIM into a spare A12 mobile and accept the two CS messages that seem to get automatically sent, WiFi calling appears. However, pop the SIM back into the S20 FE and no options.