Just to confirm, you are connecting a PC running MC acting as a Client to a PC running MC acting as a Server. So a standard Client/Server setup.
I connected my Workstation as a Client to my HTPC MC Server to test. Yes, this is broken. I think it should work as you describe.
It is possible that this fix broke the Cover Art and Lyrics display on MC when it is acting as a Controller.
27.0.13 (9/17/2020)
6. Changed: When stopped, the display window will go back to showing the logo.
Confirmed. MC27.0.12 works correctly, MC27.0.13 has the problem.
It sort of makes sense that the Spectrum Analyser doesn't display on the Client, as the files aren't being played there. It doesn't display as far back as MC27.0.1, so I'm not sure it ever did display in the Client when connected and playing to the Server. I'm not going to reinstall MC26 to check.
Clearing Playing Now for the Zone "There" doesn't result in a refresh of Playing Now either, so it looks like Playing Now hasn't been cleared until the View is refreshed. Playing Now should refresh when it is cleared.
EDIT: Lyrics aren't displayed by default, even if they are turned on. But turning them off then on results in the Lyrics being displayed on the Client. They may then disappear, but a refresh of Playing Now redisplays them. This indicates deeper problems in the Displaying Now display on the Client to me.
@JRiver, something to fix.