Are sources suppose to disapear from spotify available sources when rebooted?

I’m trying to cast from spotify to a chromecast. In the spotify docs it says:

If you don’t have any sources, then simply stream from your phone to another device in your house, bluetooth, echo, etc. Once you do the sources will show up in the developer console as a device to cast/stream to. Also know that the devices won’t show up in the dev-console as sources unless they are powered on as well.

This is not really working out for me and the sources keep showing up and dissapearing permanently, even if I turn them on in the web gui, it’s a bit unclear why. Does this work for you? Are sources that are turned of and then back on again suppose to be available?

This seems to be expected behaviour.