"You will no longer be able to use applications such as Internet, Email, or other apps that require a network connection, unless you connect to wifi etc."
The message however remains there even with Wifi on.
There is no option to clear the notification and then an Icon appears in the top left hand corner reminding you of the fact.
That top left corner of the screen is usually used for many other temporary notifications which can now no longer be displayed.
If the phone is started with data off then everything works as it did with Android 6 until data is toggled again.
Anyone know how to get rid of this notification?