Unable to enroll certain MacBooks in Device Management, "Enrollment failed. Please try again."

Previously our company had no Apple Business Manager account, and every MacBook was set up as if it were a personal device.

We completed the Domain Capture and are now in the process of enrolling the devices in ABM with Apple Business Essentials.

It's worked fine for about 22 of the devices, but 3 are still having an issue.

Trying either way of enrolling the device (Managed Apple Account email/password or downloading the enrollment profile) and then agreeing to Remote Management looks like it's signing in, and then gives an error "Enrollment Failed. Please try again."

These failed devices show up in Apple Business Manger with their serial number instead of the user's name, and under "Device Management Service" it says "No Service."

Going to the user in ABM shows they have no device assigned to them.

The three dots in the top corner of the failed devices are greyed out and not clickable.

Multi-selecting two or three of these failed devices brings up the options to "Unassign Device Management" or "Release from Organization" but neither does anything — Unassign Device Management brings up the "Are you sure" dialogue but the "Unassign" button is greyed out.

"Release from Organization" appears to work and bring up a "Devices Released" dialogue but the devices still appear in the list and in Activity I get "0 devices released" message.

What I believe happened is these users attempted the device enrollment on an old version of the OS, which failed, but that these "stuck" devices are preventing the enrollment from working now that I've had them update the OS.

Any help would be greatly appreciated. Thanks!