I have two problems trying to use BT Mobile in France. Although I am told by BT data roaming is enabled I have no data service on French mobile networks. I can send texts, and receive calls, but no email or internet. Second, when connected to French wi-fi I can receive emails, but cannot send them. Help!
When I had this exact same issue in Hungary, toggling off 4G data and dropping back to 3G fixed it. Worth a try.
What phone are you using? Are you sim only and was your phone on a different network before?
The phone is a Samsung Galaxy Ace 4. The BT Mobile contract is Sim only, and the phone has not previously been used on another network, other than normal roaming.
Could try the above. Mine didnt work in Portugal, BT told me to re-insert the SIM, switch phone off and on, select mobile networks manually until one works. None of them did, next time I go abroad I will try a 3 SIM as I didnt have any problems with 3.