Any issues with sending two step verification to protonmail? Tried logging in 3 times and no email received, I checked spam folders too. Had to use a backup code. After using the backup code, I did get an email to confirm a code has been used.
It’s either a typo, or your e-mail address is banned at the particular website. For example, a lot of temporary email addresses are recognised by websites and therefore they don’t allow you to subscribe or sign up with that email address.