You can try logging in and creating a new private key on their side. That's the only thing that links to your account. You can paste the new key on Amethyst manually. Just make sure the Alby account is the right one.

when you go to getalby.com/user you see the balance?

and then on nwc.getalby.com/alby/auth you see the application connections?

I've seen before that people had two accounts and it got confused - something we work on improving.