Cannot change primary email address on account

I’m trying to manage my ask.libreoffice.org account.
I have a login at user.documentfoundation.org.
I’ve added a second email address, and I want to make it the primary so I can delete the original primary email address.
I cannot advance past the screen shown in the referenced screen grab.
https://storage.imgbly.com/imgbly/AQg9gdznHc.png

Also, I don’t understand the Linked Profiles. I don’t understand why Bugzilla appears; I have a separate login at
https://bugs.documentfoundation.org/