Cannot authorize new laptop for Apple Music due to incorrect computer count

I've deauthorized all my unused computers, only my phone, ipad, watch and laptop (that I'm trying to add) show up in my apple account.

But when I try to sign in to Apple Music on the laptop, I get a message that I have 5 computers already authorized, so no new can be added.

How do I get iTunes and Apple Music to update their authorized numbers?