on 08-01-2019 12:55
If not then it sounds as though you are connected to the network but don't have a correct APN (access point name, the settings for the phone to use data).
The link below should help:
Please note, this is not customer services and we cannot access your account. Do not publish personal details (email, phone number, bank account).
Link to our guide on how to contact them can be found here
on 08-01-2019 12:56
There may be a problem with a mast nearby. Check your status here
Other help in this guide https://community.o2.co.uk/t5/How-to-Guides/How-can-I-sort-out-my-network-issues/ba-p/1014088
Best of luck and welcome to the forum
on 08-01-2019 13:16
@Pav check in settings that those apps are allowed to access mobile data.
OnePlus 6 (O2 & Sfr), Z3 Tablet (Three UK), iPhone 8+ (EE)