Can't play reliably on Chromecast

[michaelrkn]

I bought a couple Chromecasts so I could stream Spotify to my speakers in two rooms. When it works, it's great, but I often can't get songs to play. If I try to connect to a device or multi-room group and then play, Spotify often will show that it's playing, but no sound will come out. If I start playing and then try to connect, sometimes it will stop playing on my phone or desktop for about thirty seconds, indicate that it's trying to connect, and then fail to play on the Chromecast(s). I've tried resetting the Chromecasts and removing the group and just connecting to one Chromecast at a time, but nothing seems to help. This happened at my old apartment, where I had a modem/router, and at my new one, where I have mesh WiFi. 

Also, when a new song starts to play when the Chromecast does work, it plays about a half second, then stops, then starts again.

I'm on a Premium plan in the USA, typically using the iOS app but also the Desktop and Web apps sometimes. My Chromecasts are 3rd generation on the latest firmware (1.56.291998).

I've seen lots of people complaining about similar behavior on other sites, especially Reddit (here, here, here, and here, for example).

Does anybody have any suggestions?