Microsoft 365 E5 - Windows 10 subscription activation for hybrid Azure AD joined devices

The below mentioned GPO/registry modifications are required in order to get the Windows Enterprise upgrade.

Please Disable ‘Do not connect to any Windows Update Internet locations’ GPO/Registry key.

GPO Location:

Configure the policy value for Computer Configuration -> Administrative Templates -> Windows Components -> Windows Update -> "Do not connect to any Windows Update Internet locations" to "Disabled".

Registry Key Location:

Registry Hive: HKEY_LOCAL_MACHINE
Registry Path: \SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate

Value Name: DoNotConnectToWindowsUpdateInternetLocations

Value Type: REG_DWORD
Value: 0

Note: It may take upto 24 hrs. for the Enterprise upgrade to take effect.

Do the users login on the machine with their azure credentials? (UPN)
Make sure they are!
Also check that windows 10 license tab is checked within the licensing tab on the users

Also I hit a wall doing this because of the licensing on the machines today for different reasons! Are you sure the machines have an active Win10 PRO license?
Try running this script on a test machine:

(Copy the text below into a .cmd file and run the file from an elevated command prompt:)
@echo off
FOR /F "skip=1" %%A IN ('wmic path SoftwareLicensingService get OA3xOriginalProductKey') DO (
SET "ProductKey=%%A"
goto InstallKey
)

:InstallKey
IF [%ProductKey%]==[] (
echo No key present
) ELSE (
echo Installing %ProductKey%
changepk.exe /ProductKey %ProductKey%
)
..........................................................
That solved it for me!

You seemed to get the join process right so you’re pretty close now :)