I should mention that I am using the pro version.
Other weird behaviour include:
Cannot make the “nickname” field not required even though it is checked as hidden, and when I try to make it visible, it doesn’t show up
I received the following feedback from a user:
Actually, I did manage to log in through the bug by clicking on the button like 50 times. In fact, in Safari there is a button problem and you can see a “?” blinking when you move your mouse through the button.