Data keeps stopping working

[Mads.]

Brought a new iPhone 6 months ago with sky, but ill be out and about and randomly the data just doesn't work, I have signal says I have 4G/5G but my phone will not load anything. 
The other night I dropped a friend off and went to use my maps to get directions home, and it wouldn't load! had signal and 4G, turned my phone off 4 times tried turning airaplane mode on and off took 20 mins for it to work again and I had no means of getting home without it! 

[Cmmanners]

This is happening to me and both my kids phones . It's really frustrating. I have no idea how to fix this unless I go with a different service provider . The chat service doesn't help .