TeamCity Enterprise: Can't choose my uploaded SSH key when configuring the VCS root

The reason I am posting here is because your Enterprise support form is broken. Nothing happens when I click Submit.

Trying to integrate a new TeamCity project with an existing git-bitbucket repo.

I am a rather limited user on our TeamCity platform (on-prem, 2017.1.3-46961). I do not have access to the actual server file system, I am using the web interface, instead.

Created an SSH key pair on my laptop with ssh-keygen -t rsa -m PEM

In our TeamCity, I uploaded the SSH key (private side): enter image description here

However, when trying to set up my VCS root with that key, I cannot see it in the drop-down: enter image description here

This VCS Root is in the project where the SSH key has been uploaded. Should have I uploaded the key somewhere else?

Or, maybe, this is a TeamCity bug? I tried basic shake-up like hard-refreshing the page, logging out/in...