How do you get the Fritzbox to show a text field for admin login rather than a dropdown?

I created a new user on my Fritzbox from my phone, over the Fritz VPN. Back on the wired network when I try to log into the Fritzbox 7590 I now have a dropdown showing two users, the one I just created and an older user that Home Assistant. I can't find a way to login as admin. Has anyone had this happen and found a solution? Until I created this new user (which I have forgotten the password for, whoops) I always got a text field.

I can log in via another user I created ages ago, but having access to the admin user seems like it should be useful.

I have a recent backup of Fritzbox settings so I could reset and restore, but I'd rather fix it if I can.