Oh, that's funny, haha. Let me explain why.
To run the advanced display features (especially around the webcam), Apple put an A-series processor and iOS software in the Studio Displays, like one used in recent iPhones. But the Studio display has no possible path to the Internet.
So it shows up as a "ready to go" network interface, but with no Router willing to talk to it.
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My advice would be to use the gear icon under the list of interfaces in System Preferences > network ...
to 'set service Order' and drag the Studio Display to the bottom of the list where it is easier to ignore its non-connection.