I was having the same issue since updating to iOS 14.2 didn’t really realize it because I was at home connected to WiFi all the time but thanksgiving forced me out of the house to get food and what not and that’s when I realized that my data wasn’t working at all I contacted apple and went through all the steps even resetting my phone completely still the same issue so today I contacted my carrier and they reset some settings on their end I’m assuming and told me to reset my network and power phone off and on and then toggle cellular data a couple times and now it’s working I’m hoping it holds up if not I will update