Refuses to 'log in' instead of 'sign up'

I was forced to create this account by the Hub integration - even if I click ‘log in’, even from the ‘sign up’ window, it always goes back to ‘sign up’ with the email pre-filled in and unmodifiable. The account I have used in the past is @pie_flavor and I could find no way of logging into it. I tried switching my Hub email to the email associated with that account, but all that did was make it impossible to use the ‘sign up’ form (as the email was already taken) - it still brought me to ‘sign up’ every single time I tried to ‘log in’ from any flow.
If possible I would like this account merged with @pie_flavor, keeping that name, and for it to actually understand that I want to log into my account instead of sign up for a new one.

I believe this is a Hub issue, please file a ticket here: