Okay, since I’m not using spotify I have no idea about those plugins. But bottomline: If a media plugin, i.e. a plugin that serves an audio stream to volumio, regardless of the source, does not properly implement Volumio’s policy of sending websocket events for play/pause/stop, etc. then the plugin will not trigger AmpSwitch. This however is not a flaw of AmpSwitch, but of the plugin that does not communicate it’s status. I therefore suggest you visit the author’s GitHub and report an issue about this.