Why are some/all Device/Site names not displaying what I expected?

Because the “Device display full name” option in “Console screen” option Preferences is not set to what you want.

If it’s not set, it will simply display the “name” of the device as per its “CAM Address” (last part).

If it’s set, then it will display the “full_name” of the device. This is set in the CAM/Identification panel for the device.

NOTE: this option affects both “Console screen” and “Device explorer” display.