Hi Steve, just to add my experience for info. Like The Wee Bear I have also purchased a prepaid unlimited EE sim via Amazon (Seller is Scancom). These services are not functioning on my home network:
- WiFi Calling / Whatsapp voicecalls
- Smart TV streaming services (Netflix, Apple TV, Youtube).
- WiFi security cameras
- Spotify streaming via Chromecast audio
My laptop and iPhone connects to the internet and gets up to 100Mb down (might be capped at 100Mb?) and can stream all services, just the WiFi calling / Whatsapp that isn't working. My wife can't connect to her company's servers via VPN either.
I am using a Huawei B535-333 and am not getting an external IPv4 address, only IPv6. I have even tried some of the excellent suggestions from
@EssexBoy on the EE forum (including changing APN to force IPv4 but no joy as won't connect).
Pop an EE PAYG or Three sim in, boom. No problems and everything works. So the preloaded sim from Scancom is perhaps not able to use IPv4 (I think EE might have switched it off in favour of IPv6 on in 2018, maybe just on data only sims but this is only a guess). Or, as
@The Wee Bear says it might be CGNAT issues. I have tried a DDNS via the router but couldn't get that to work and my router only supports slower VPN protocols which may solve the issue.