Mobile Data Network not Connecting after moving away from WiFi range

Hi Guys,

A number of us are having the same issue on iOS 11.1.1, 11.03 and 11 etc. of iPhone 8 and 7

When connected to a WIFI network and then leaving it the phone does not connect to the mobile/LTE network. We have to go to airplane mode and then back again for the network to connect. it then works fine.

It also works fine when switching from Mobile to Wifi and the minute you leave wifi again you have to turn airplane mode on and off again to get mobile network. Bluetooth works fine.

Any advice please. Have rebooted, checked for carrier updates, reset network and tests so far.

Frustrated Frank