BUG: Spotify iPhone app fails to control Chromecast with "don't like" songs

[mattled]

Plan: Premium

Country: UK

Device: iPhone 7 Plus

My Question or Issue

I use the Spotify iPhone app with Chromecast Audio. Somewhat regularly Spotify gets the Chromecast Audio into a state where it cannot control it and is also hard to reconnect. I notice this most of the time combined with this issue, which makes it a very frustrating experience of not being able to skip a song I don't want to listen to, and told Spotify before that I don't want to.

The Chromecast Audio is playing music from Spotify and I want to skip a song. I open the Spotify app on the iPhone. The pause/next song controls are not working at all, it typically also does not show the song that is currently playing. Opening the menu to connect to the cast devices shows it as connected to the Chromecast. Selecting "This iPhone" and then the Chromecast again, does not reconnect to it. Restarting the iPhone app does not help. I was also able multiple times to play Spotify on another Chromecast at that point in time, without Spotify disconnecting the first one.

To understand how to recover this state, I discovered the following:

(1) The Google Home app is most of the time still able to pause the song.

(2) Other apps (tested with TuneIn Radio) are still able to connect to the Chromecast.

I've not managed to get Spotify to reconnect on its own. I managed to reconnect after rebooting the Chromecast Audio and in the latest attempt after TuneIn Radio connected to the Chromecast. This leads me to believe that the Spotify client on the Chromecast Audio gets into a bad state and cannot recover on its own without being restarted. I've observed this issue on two Chromecast Audio devices.

I will try to collect more information on what is necessary / possible to make it recover from this state the next time it happens. If there are any specific things I should test, pleae let me know.

[mattled]

Happened again while playing the "don't like" song from my Discover Weekly. Spotify app did not show the song, play/pause did not work, disconnect/reconnect from within the Spotify app, even after restarting it. After "Stop Casting" from the Google Home app, the Spotify app was able to connect again to the Chromecast.

This appears to happen basically ever time the "don't like" song that is playing that I expect the issue may be related to this.

[mattled]

I managed to reproduce this:

(0) I have a Discover Weekly with a "don't like" song already, which is grayed out on the iPhone app.

(1) Connect Spotify to a Chromecast Audio.

(2) Shuffle Play the Discover Weekly playlist

(3) Go to the "Playing from" menu to reorder the queue of songs to play.

(4) The "don't like" song is in this list and can, move it to the first item in the queue, after the currently plaing song.

(5) Wait for the end of the current song (you can seek near to the end to speed up this step).

(6) The "don't like" song starts playing, the Spotify app looses control over the Chromecast Audio and cannot reconnect by its own. The Spotify client has to be independently disconnected from the Chromecast Audio (e.g. Google Home app).

This looks pretty much like a bug in how the Spotify iPhone client and the Spotiy Chromecast Audio integration handle "don't like" songs.

Some more observations:

(1) When the "don't like" song is queued up to be the next song, and manually clicking the next song button in the iPhone app, the song is skipped.

(2) I tried to reproduce this on Android, but the "don't like" song does not even appear in the queue of songs to play. I.e. the UI behaves differently w.r.t. don't like songs on iPhone and Android.