The team at Virgin Mobile understands some customers may have recently been affected by services not working as expected over 3G and 4G data including Siri on iOS11 - we believe this should now be resolved for our customers.
We apologise for any inconvenience this may have caused.
Update since my last post , all not quite as good as I thought. still having issue with browsing even with full 4G signal, says connection was lost .As others have mentioned if you switch flight mode on and off it recovers and works ok .
And now I cannot get on the iTunes Store app using 4g, its saying cannot connect to iTunes Store but I can through WiFi I have restarted my iPhone 8 still the same! My iPhone 6 32gb with your old SIM card works fine and I still have to keep switching my phone to airplane mode when I come off WiFi to get mobile data to work! I have been with virgin mobile for well over 10 or more years now this is the first time I’ve had any problems with your network so all I can say is some where there most be something wrong!