An Entra Cutover is showing as completed but the device has not joined the target tenant.
Within the Event Viewer\Applications and Services Logs\Microsoft\Windows\Provisioning-Diagnostics-Provider\Admin logs you see a 0x8018000A error.
You can also see source tenant information in the following registry keys
Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\CloudDomainJoin\
Having source information in the registry keys prevents the package from running correctly and joining the target tenant.
This can happen when the device is Entra Registered rather than Entra Joined.
The cutover will look if the device is Entra Joined and run Dsregcmd /leave which will remove those keys
Dsregcmd /leave will not remove keys on a Entra Registered devices.
Entra Cutover is not supported on Entra Registered devices.
Create a custom script to run before cutover which will clear the keys for the source tenant in this location
Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\CloudDomainJoin\
This will allow the Microsoft package to add the device to the target tenant
