Airport Time Capsule

Apple's firmware and operating system are not exactly bug free. Sometimes, the device name is displayed, at other times an IP address is displayed and yet others the MAC Address or WiFi Address is displayed.

It's been that way for a few years since the 6.x versions of AirPort Utility were introduced.......and apparently remains very low on Apple's priority list of bug fixes.

Try the following to see if anything changes:

Power off the Time Capsule

Wait a few seconds

Power the Time Capsule back up for a few minutes

Open AirPort Utility on your Mac

Hold down the option key on your Mac while you double-click on the picture of the Time Capsule

A list of wireless clients will appear

Click on the small arrow next to each client for more info about the device

There is no logic, but it does display the client names most of the time when I try this. Sorry, that it does not seem to be working for you.

Power on the Time Capsule....and then....wait a few minutes.

Then....open AirPort Utility and follow the other instructions that I listed.