Email Guardian could not add my Hotmail/outlook email

I am trying to add my Hotmail/outlook email account in email guardian mailbox list, but it is showing a message that “another user added this email”, in the past I added it successfully with no problem by using the same user account, then later I removed Avast email guardian connectivity in my Microsoft app management account. Now I am not sure why this issue happened; any advice?
Note that I uninstalled and reinstalled avast security premium.