I have just upgraded my iPhone XR to an iPhone 12 Pro Max, this came with a new SIM card, I have followed the instructions to update the sim by texting 20220.
My old SIM then stopped working, my new Sim started working in my iPhone 12 pro Max, after an hour it has stopped working, my iPhone connects to Wifi but does not allow me to open anything online (Safari or apps)
i put the new updated SIM into my iPhone XR and this works fine so it's not a SIM card issue.
Some iPhones are shipped with a temp bar on them to deter theft.
Call O2 to have it removed Guide: Coronavirus Community Help and Support
I sort of got it working.
I removed the SIM, added my old one then re insert my new one.
it has been working for about 2 hours, now saying 4G and can connect to the WIFI but acts as if it's on airplane mode, by this I mean it can not load any new web pages or online apps. I will call O2 about the network.
Track usage, upgrade and get support with the My O2 appDownload My O2