Settings > Connectivity > Mobile networks > Select network picks up all the networks, but it just goes back to "emergency calls only" when I select one. The "preferred networks" menu used to list operators all over the world but is now blank. I've manually added O2, Orange, 3 etc back to the list but that hasn't helped.
I borrowed a Vodafone UK SIM and it connects straight away with no issues. As soon as I put my Telecom SIM back in, it goes back to the emergency only screen.
Does anyone have any ideas?