Frankly,  I haven't encountered similar problem in the past, nor do I recently work much on Windows Modern device platform.  So, the following are just based on my educated guess.

Have you tried deleting the device icon corresponding to the already enrolled Windows Classic device?   Or uninstalling the device agent associated with the Windows Classic platform?

Have you configured Windows Notiification Service (WNS), which is needed  for more responsive control of Windows Modern device? 

Hello Jeff, 

Thank you for requesting a response from SOTI Support Staff.

I have consulted our Development team and it sounds like you are experiencing an unfamiliar problem.  I have never tested the 2 methods to enrollment together but I wouldn't expect a device to take over a previously enrolled device in the console.  Usually, when this occurs it is an error.

Are you looking to take advantage of the features of both at the same time or just using it as your provisioning workflow?

As Raymond and our developer has suggested, try unenrolling the device from Classic before you re-enroll it into the Modern platform.

If you believe you have a use case for the original scenario, feel free to create a support case and we can address it with our development team and/or document the expected behavior for more of a long term solution. 

Regards,

After reading your reply and checking https://www.soti.net/mc/help/v14.2/en/console/devices/managing/removing/unenroll.html I see this is most likely what I need to do.

1. Unenroll the device from Classic

2. Let the provisioning package re-enroll the device to Windows Modern.

The issue is I do not see an option to unenroll devices as stated in that guide. From my SOTI console I only have the option to Delete the device, when I delete the device it still retains all of MobiControl Agent's information on the device itself. 

Hello Jeff,

Looks like the device is having identity ambiguity in the server.

In addition to what @SupportStaff and Raymond posted, Just Un-enrolling from MobiControl and deleting it won't delete the files. Make sure during the un-enrollment process there is no files in the device related to MobiControl. Look for "MCSetup.ini" and "Pdb.ini" before enrolling it as Windows Modern.

2 files mentioned above are the one which contains the enrollment details of the Deployment server which it is connected to with its related certificates. Deleteing these 2 files will mean that the device no longer has the enrollment details to connect and will be open to new connections.

Also make sure the device which is being enrolled as Modern should be Windows 10.1703 or later. 

Thank you.