Unable to access Founders Hub portal - M365 benefit redemption blocked

I am an approved Founders Hub member with an active $1,000 Azure credit and I am unable to access the Founders Hub portal or redeem my Microsoft 365 Business Premium benefit.

I have already contacted Azure Billing Support regarding this issue, but I believe this falls under your team's remit rather than billing, so I am reaching out directly.

The issues I am experiencing:

1. portal.startups.microsoft.com/login only offers a "Log in with LinkedIn" option — my Founders Hub account is not linked to LinkedIn, so this does not work for me.

2. Clicking "Log in with your Microsoft account here" redirects me to portal.startups.microsoft.com/signup, which is the new user signup page — not a login page.

3. Navigating directly to portal.startups.microsoft.com also lands on the signup page with no way to manually enter my Microsoft account email.

All roads lead back to the same circular loop with no resolution.

My Founders Hub account is registered under a gmail not my custom domain. I am fully signed into the Azure Portal (portal.azure.com) with this account and can confirm my Azure credit is active.

What I need help with:

- Accessing my existing Founders Hub account

- Redeeming the Microsoft 365 Business Premium benefit

- Setting up a Microsoft 365 tenant so I can use Teams under my custom domain

Please advise on how to proceed.