I've saw this before. Open up Credential Manager and delete anything related to Office. Don't just edit and verify, actually delete it. When you sign in again, it'll store a new copy. Happens sometimes with password changes or a bad sync between password changes.
Can find it in Control Panel or just search for it.
Hence why Apple products are working OK... They don't have Credential Manager. Same thing happens with Keychain on Apple PCs sometimes. But the mobile devices obviously don't have Keychain.
Apple products are NOT working okay, they are half working.
There was a contact us email address in VLSC. I wrote them, included my license key and business information. They wrote back today indicating that they would create my key and I would receive it in a separate email. Additionally it would be added to my VLSC account.
I actually received the email with the KMS key before this email, and sure enough, the KMS key is now in my VLSC account.