Stuck on Infinite Login Loop Signing Up for Microsoft Partner Network - can't make account

Question

I'm working on a functionality to enable a registered application in my directory to allow for multi-tenant OAuth2 which requires signing up for the Microsoft Partner Network (MPN) and getting a MPN ID.

I'm having an issue, however, where I'm unable to sign up for MPN as I'm stuck in an infinite login/logout loop (I've attached screenshots for reference). After logging in for MPN, it prompts me to press next, and when I do that it prompts me to signout — I never get to actually sign up for MPN.

How can I sign up for MPN?