FYI ios 12 devices can't be enrolled with profilemangers without a valid FullyqualifiedName
Looks like if you don't have a fully qualified name with a valid ssl cert, ios 12 devices can't be enrolled.
You'll get a "a network error has occured" during the DEP enrollment process.
This also happens if you try to manually do it in "My Devices".
This is with 5.6.3
Did not try it before the update.
iOS 12, profile manager