I can't change the primary email on Adobe ID for Behance

Hi! I am trying to change my primary email address on Adobe ID for my Behance to one I previously used with a deleted Behance account (I have confirmation that the account was successfully deleted). However, every time I enter the new email, I get a message saying that this email is already in use. I thought it might be because the email I want to switch to is used as a backup email for the account. But I tried removing it from the list of additional email addresses, and the error still appears. I would appreciate any help.