Can't remove devices from iTunes - all "remove" buttons greyed out.

When trying to view/play my iTunes content on a home laptop, am getting message telling me that I've max'd out on th 10 devices permitted by iTunes and that I should remove one from the list if I want to add a new device. Problem is, all "remove" buttons next to the devices on the list are grayed out and not selectable, and showing '30 days remaining' for all associated devices, even when some devices were associated as far back as November 2019 (how can 30 days still be remaining?).

What can be done to restore functionality to "remove" buttons so that devices can be managed?