Can't enrol one PC to Win10 ESU

I paid for the ESU program and one of my 5 PC's refuses to enrol. The latest 22H2 and other updates are installed, it's signed in with my MS account as Administrator. location services are on. I tried changing to a local login and then back to the MS account and that did not help. Windows Update reports "Your version of Windows has reached the end of support" and there's no "You have enrolled..." text on the right on the Windows Updates page as there is on my other computers. When I try taking the steps to enrol it in the ESU program I get an error message after entering my Microsoft Account info (which the computer's already using to log on ..) 

It's not a computer I use often, so there's no huge rush to fix it. But I'm wondering what steps I can take to fix it?

I tried doing a chat with MS support but they suggested I try "Microsoft Community Support page for assistance" first: "Microsoft still has a dedicated support team available to assist with ESU enrollment issues. That’s why I’m recommending you reach out to the Windows 10 ESU support team directly—they can help verify your device’s status"  .... I assume they mean here??

Thanks for any help.

R