Scenario: I have completed the Account Update page and marked my cell phone number to allow for multiple users. I then completed the Account Update page and successfully entered the same cell phone number for my 2nd username. Now, I am receiving an error that the cell phone number must be unique for the third user name.
Work Around: Go back and check the cell phone box in the original username. You will need to do this when you attempt to update each third username.
Solution: We will make a fix and release it.
Blog posted 09/22/2017