Chromebook won't connect to chromecast from spotify

[joshing]

I've never had this issue before, and it works just fine casting from my phone (iPhone7) but when I try to cast from the webapp on my chromebook, it shows the spotify logo on my tv screen, then immediately disconnects. I've tried reseting the chromecast and the chromebook, and wiping all the browser data. It connects if I cast the whole desktop from the chromebook's settings, but then the audio is spotty. 

[brianwh]

I just bought an ASUS Flip Chromebook and I am having the exact same experience.