I enter my username, matching passwords, and email address, and click register, but it returns me to the same screen, with the password fields deleted. I have not received any registration email.
developer here. First, it’s clear that there is a User Experience issue, as you don’t receive any feedback after a not successful form sending.
Nevertheless, if your password are matching, it boils down to this issue: either your username or email is already taken. This might mean you already registered before.
Please contact us per: saluton [ĉe] pasportaservo·org