Returned XiFi Gateway still showing in My Account App

My XB3 gateway died today so I went to the Xfinity store and grabbed a XB6. Sadly, the XB6 was dirty and broken when I arrived home and took it out of the plastic. I did try to connect it, but it didn't work. Surprised Xfinity doesn't clean refurbished devices during COVId, but that is besides the point. 

So I went to a diffrent Xfinity store and returned the XB6 for a XB7. 

The XB7 is working great, but I noticed in the My Account app that the returned XB6 still shows along with the XB7. I also noticed that under phone the XB6 still show as my voice gateway with the new XB7 listed under it, but without my home #.

The XiFi app only shows the XB7. 

Why does the returned modem still show in My Account devices for Internet and Voice?