As @Zoex I have the exact same problem. I’m using iPhone XS with iOS 14.2 and ever since this update I cannot turn the toggle on for no matter which app to use my internet data volume when I’m outside and have no WiFi connection from somewhere. I tried all of the recommendations here (except the “reset all of the iPhone settings” because I don’t want to do that. At least not yet) and nothing worked. Can someone please help solve this terrible problem because it basically renders the phone unusable. I hope Apple notices this problem and fixes it ASAP with the next update. Thank you very much  P.S. turning on/off vpn or completely deleting the app also didn’t work...

I have the exact same problem. I’m using iPhone XS with iOS 14.2 and ever since this update I cannot turn the toggle on for no matter which app to use my internet data volume when I’m outside and have no WiFi connection from somewhere. I tried all of the recommendations here (except the “reset all of the iPhone settings” because I don’t want to do that. At least not yet) and nothing worked. Can someone please help solve this terrible problem because it basically renders the phone unusable. I hope Apple notices this problem and fixes it ASAP with the next update. Thank you very much 

Same problem here. Did the same things as @KarenL but still have the problem. It didn’t solve anything and since I don’t want to reset all my settings can someone please help with other alternative solutions for this horrible problem. Thank you very much

Yes I have the exact same problem as @jodles but I still have it even though I’m using iOS 14.2 please help what do I do? Thanks