APNs, good. DEP, good. Devices listed under Enrollment status, Yes, OK.
If the serial numbers are NOT listed, do this:
1) Groups and Settings
2) All Settings
3) Devices & Users
5) Device Enrollment Program
6) Under Token section, 'Sync Devices'
Once you can see the serial numbers under the Enrollment Status page, continue:
Then try this:
1) connect the iPad to a mac os client running Apple Configuator.
2) When the device is connected, what is the activation status?
--> Anything other than 'Unactivated' will make it fail.
What to do? In Apple Configurator 2, Version 2.9 (3J40)
3) Erase All Content and Settings
These steps work for me and this is the reason I believe why...
A device enrollment was attempted, however it failed becuase the device was not yet discoverd by AirWatch. When you try to provision again without a full device wpie (Erase All Content And Settings), the serial number check has already been done and therefore the device activation record is already set.
Erasing all Content and Settings reset the activation record, forcing the iPad to go back to the Apple servers.
This is what I think it happens.