I have arrived in the USA and my phone hasn't welcomed me or found another network, since it can't connect to Virgin here, both of which it usually does. Why is this? I have switched on Roaming, by the way.
Welcome to the community and thanks for posting. I'm sorry to hear the news your phone isn't connecting to a network in the USA. This clearly isn't good if you need to contact home.
Even though roaming shows as active, there may still have been a problem when activating it on the EE platform. You could try resetting it your end.
You can now do this via your online account. Please click here to log in and follow these steps:-
Online account > Plan and device > Manage services > Going abroad
If it shows it's turned on then please turn it off. A green message will appear. You'll need to wait 2-24 hours for this to be successful. Then you repeat the process to turn it back on again waiting a further 2-24 hours.
If this fails, and you can get to a phone, then the next step would be to call the team on +447953967967. They'll be able to check the network over.
I'd be very keen to hear the outcome so please keep me updated.
I did as you suggested and turned off roaming but when I went beck into my account 12 hours later, I noticed that somehow it had been switched back on (without me doing anything) and I still cannot find a mobile network service. I have been trying to telephone the number you included as a link but it keeps saying the system is busy and to try again later. I am not impressed by the amount of time and energy this is taking up, particularly since I have been trying to sort this out myself since Wednesday afternoon, after I landed, before contacting you.