How do you rename an AirPlay device?

In my current setup I have two gen 4 Apple TVs which are named "Living Room" and "Office," respectively in the AirPlay > Room option for each unit ... and they still show up with these names on each respective ATV.

Everything was working as expected using either my iPhone SE or iPad Pro running iOS 11.4 with both ATVs having these names from the AirPlay selection menu. I then tried to use the Home app on the iPad and managed to rename the Office ATV to Family Room. It now shows up from any iTunes host as "Family Room (2)" Obviously, I was having a "doh" moment and didn't mean to rename the Office ATV.

So, my question is: How do I rename my "Family Room (2)" ATV back to "Office?" Again, the room name for the Office ATV does show up as "Office" on the ATV, but "Family Room (2)" from any other device.