Thanks but I don't have a data limit to change. It's just an (unfortunately) known Oreo bug. Just google it, and you are going to find out google...
I am not happy with Oreo update. I have an message "mobile data has run out", although I have plenty left
So no mobile data connection yet :(
You are lucky that you haven't updated to Oreo. After my update I have lost the data connection, and I see people have some other issues too.
I have the same problem, after Oreo update. Any official fix?