Cannot update user's phone number

I use “Update user” method to change a phone number:

PATCH {domain}/api/v2/users/{id}
Body: phone_number, connection, client_id

Sometimes I get an error back: “The specified new phone_number already exists”.
However, there are no users with this phone number in my Auth0 tenant. Even after deleting all users, I still get this error.

Hey there!

Welcome in our community! Could you send me your tenant name and that user id over private message so we can investigate that?

Thank you!

Hey there!

Terribly sorry for such huge delay. We’re doing our best in providing you guys with the required developer support experience but sometimes the number of incoming questions for our three people team is too much. I just replied in our private thread. Once we have it figured out I’ll share it here!