Cellular Update Failed

My iPhone 7 has recently received a notification with the following message: “Cellular Update Failed - your iPhone cannot make and receive calls or access cellular data until it has been updated.” It has happened a couple times in the past few weeks, but I’ve just restarted my phone and the cellular data and service has been fine after every time. But last night it happened again, and nothing I do seem to fix it. What is going on? What do I need to do to solve this problem? For me personally, it’s pretty pointless to have a phone if I can’t even use it, so this is very frustrating, especially since most of my day is spent where there is no WiFi.

ps. I’ve checked my phone carrier, and there is no issue with that. It’s something going on on the phone itself.

Please help!