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 Do not publish personal details (email, phone number, bank account).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
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
Veritas Numquam Perit
@Pav check in settings that those apps are allowed to access mobile data.