I have Moto G4+ and I was playing around with
*#*#4636#*#* and accidentally set the radio band to USA Band. Now there's no way of changing it back, so now I can't even connect to a network, let alone use data.
I've searched for this issue and it appears that there were other people with the problem, but all of them didn't have answers. The only possible answer was to flash the ROM again, but there was no confirmation of it having worked.
And anyway my phone isn't rooted, and I don't want to root, since it is new, as well as the fact that it's not easy for the Moto G4+.