TV / Media Player - where are sources in the UI? What about scripts?

In the configuration, and only in one specific configuration screen, I see the following for my Bravia TV:

Why can’t I see these in any other location other than this one specific, slow loading config screen? (it doesn’t seem like this info is cached, and it polls the API every time)

Sidenote: this happens if I try to add the device to “Lovelace”

Add a media player card to your front end, with the TV selected as the entity. Then turn it on.

Ah yep, the second time around I see sources:


The ‘turn it on’ bit might have been the thing you were missing the first time around. The media player needs to be on to view the source.