Check the apn is set to mobile.o2.co.uk in the Mobile Data Settings
Your data apn should be "idata.o2.co.uk"
If you just select to reset network settings it will add the correct apn details.
Also go to Settings >Mobile data and scroll down to ensure data connections are turned on for your apps.
Heye @LS1992 were you able to get your data working?
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