on 15-07-2020 09:30
on 15-07-2020 09:49
Have you checked the network status here ? O2 Service Status
Is it everywhere or just in one location?
If everywhere, you may need a new sim or have a faulty phone.
If just one location, it may be that O2 isn't the best in that area and a change of network may be required.
on 15-07-2020 09:54