Fixed the connection step approving and refusing the same account
In rare cases, two checks of the same account ran at once during the connection step. One approved it and let you continue, the other refused it a few seconds later, and the step after payment failed each time you tried again. The check now runs once per account: you see one answer, the one you can act on. If your account is refused, the reason is shown to you right there, with the field to correct.