iPhone No Data Network

[AlanJ1234]

I have a 2 and half year old iPhone SE. Since last September's IOS update i get the following error message when going into a non wifi area. "Could not activate mobile data network Turn on mobile data or use Wi-Fi to access data" Despite have a full mobile signal and 4G all showing on screen. I turn on then off, airplane mode and phone works fine. Apple have tried to resolve the issue to no avail. The phone is out of warranty so they suggest buy a new phone!! EE my network provider have replaced sim and tried to determine the problem also to no avail. A Vodaphone sim works fine with no error message. Recently abroad I put in a pay as you go data sim with no errors. Has anyone experienced a similar problem. I only get an EE signal where I live so don't want to change providers