Wifi-calling not working on newly activated replacement SIM

[labrat1]

HI, I spoke to a SKY advisor about wifi-calling not working, he checked the records and said my SIM serial number was from 2001 and so didn't support WIFI-calling. So he said he would post me a 2025 replacement SIM. It arrived yesterday. Today I ACTIVATED it and took out the old SIM and replaced it with the new on. Switched on the phone, but WIFI-Calling still appears not to work. Note I have NOOB FULL fiber to the house, and there is nothing wrong with my WIFI. I confirmed this but trying a GifGaf SIM card in the same phone an ARMOR 9  (with android 10), and WIFI-Calling works no problem. I only have the problem with a SKY SIM card. Please help. The 02 cell coverage is very poor at home, that is why I need WiFI-Calling to work.

[caesarome]

@labrat1 

Was your phone from Sky because if it wasn't Sky do say that wifi calling might not work:

https://www.sky.com/help/articles/wi-fi-calling

One to watch out for: If you didn't get your phone from us, it might not be compatible with Sky Mobile WiFi calling. To check, set up WiFi calling and try making a call over WiFi. If the ‘WiFi call’ indicator doesn’t show, then your phone isn’t compatible.

[labrat1]

Its an ARMOR 9  (with android 10) not from SKY. But I tested it with a GifGaf SIM and WiFI-Calling works in that phone. Is there something different in SKY's implementation of WIFI-Calling thats stopping it working then? As I said in my previous post The Sky Advisor I spoke to a couple of days ago said my original SIM was too old, and he said this new SIM should work, but it dosn't :(. 
If it dosn't work by tomorrow, I'l try another phone (That ones a Samsung A16  that did come from SKY).

[63johnw]

Hi @labrat1  as mentioned if you didn't buy the phone from sky then they don't guarantee WiFi calling will work. This will be the issue, even if the feature works with other networks.