Hi Silas Leno, I know how frustrating it is to have a valid code and still see that error it feels like you’re stuck waiting with no clear reason.
First, check Microsoft service status to rule out outages. Make sure your account region matches the product key clear your browser cache or try another device confirm your account verification and redeem the code at redeem.microsoft.com. If it still doesn’t work after a few hours contact Microsoft Support with the error details.
Have you checked if your Microsoft account region matches the region of the product key or tried redeeming the code through redeem.microsoft.com instead of the setup page?
Best regards
Lucky