It's likely that one of your users has been assigned a number but also has that number entered in the Phone field in their user settings if you hear a loop on phone calls or see lots of calls stacking up in Conversations.
If you're hearing a loop on phone calls or you're seeing lots of calls stack up, one after the other, in Conversations, odds are one of your users has been assigned a number but also has that number set in the Phone field in their user settings.
