Data access issues with 3G and 4G. Internet only with Wifi

[Zygomaxilla]

Please can someone advise what my my mobile data network settings should be. I lost access on Sunday afternoon.

I thought it may be a network outage. I downloaded the O2 network app. And it reports no problems. It seemed to come back for a few hours and is now off again.

My iphone shows full 4G signal. But I can only send and receive data on wifi.

[MI5]

For what type of phone @Zygomaxilla ?

Have you checked for issues here O2 Service Status

or rebooted your phone since the issue started?

[Zygomaxilla]

Hi I gave up trying to phone O2 support.

Apart from getting some tips from MI5. I found the whole ask the community pretty useless.
But I suppose it depends on the captive audience of who knows how to help.

I tried using the O2 chat service and there was no one available. After my whole life with Vodafone I almost quit O2 after only 2 months of service.

However I watched the O2 video about network issues. And then used the tool which asks what phone you have etc. It suggested my SIM was the issue. To me it seemed unlikely. But 24hrs before network loss I had installed the latest IOS update.

I reset the network settings. Powered down the phone as suggested Airplane mode, then power off. Removed the SIM card. And powered back on. And bang no more network issues.

Resetting the network settings for mobile data did nothing other than changing some of them to Vodafone where the phone initially was a contract vodafone.

Taking the SIM out and reinserting was the answer. And one forum I read suggested IOS updates often corrupt settings. And mobile data settings are installed on the SIM card.

So problem solved now.