Desktopsharing: confusing and not working configuration

I try to limit the screen share options to “window” only: desktopSharingSources: ['window'],

But this limitation does not work.

Furthermore the config in the source of https://meet.jit.si/ is even more confusing:

  //deprecated desktop sharing settings, included only because older version of jitsi-meet require them
    desktopSharing: 'ext', // Desktop sharing method. Can be set to 'ext', 'webrtc' or false to disable.
    chromeExtensionId: 'kglhbbefdnlheedjiejgomgmfplipfeb', // Id of desktop streamer Chrome extension
    desktopSharingSources: ['screen', 'window'],
 ...
    //new desktop sharing settings
    desktopSharingChromeExtId: 'kglhbbefdnlheedjiejgomgmfplipfeb', // Id of desktop streamer Chrome extension
    desktopSharingChromeSources: ['screen', 'window', 'tab'],

“New” and “old” are mixed up. As a result the setting desktopSharingSources: ['screen', 'window'], does not work on https://meet.jit.si/ either.

The issue gets mentioned, but without any clarification:

I would highly appreciate help about which settings are necessary to make this work!