How to resolve 'Your Apple Account has reached the maximum number of devices' error in Apple Business Manager?

I am attempting to add a new device to a user on my company's Apple Business Manager, but we keep receiving the following error when this user logs into their new device:

The MDM server responded with this error message:

Your Apple Account has reached the maximum number of devices associated with it. Contact your administrator to upgrade your subscription.

This user had all three device slots filled (iphone, ipad, macbook air), I removed the macbook air on Apple Business Manager to free up a device slot since we now have a MacMini for this user, but the error above prevents the user form being able to log in. This change was made about 6 days ago at the time of this post.

This user only shows two device slots in use on their profile in ABM. I don't know if I missed a step or if something is wrong on the back end. Any guidance would be helpful.

Thanks

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Original Title: Apple Business