unable to verify my academic status for azure

Question

I have already received the verify email and click the link, but it navigates to the page of Student Verification and ask me to enter my school email again. And after I enter my school email, sometimes it says "We encountered an unexpected error. Try again later.", and sometimes I enter the portal but still didn't verify my academic status.

Our university ask us to follow a manual, which ask us to sign up with our school emails, but we can only sign up with our personal emails.

I wonder which step is wrong. Or did our university's subscription expire?