Why there is a prompt that the doorbell is bound with other accounts when binding the Xiaomi Smart Doorbell 3S in the APP?

The Xiaomi Smart Doorbell 3S can only be bound by one Xiaomi Account. After bound, the doorbell cannot be bound with other accounts. In addition, you can log in to the Mi Home/Xiaomi Home APP via the phone number verification code, the password of the Xiaomi Account and the password of the email. If your account is not bound with a mobile phone number, each login method will generate an associated Xiaomi Account. When you log in to bind the doorbell using any of the above login methods, and then change to other login methods, there will be no doorbell in the new account. No other account can bind this doorbell until the original account has been unbound.
Note:
You can check whether your Xiaomi Account is bound with a phone number by going to the [Mi home/Xiaomi Home] APP >> [Profile] >> tapping the account at the upper left corner to enter the account information.