Just to make sure we cover all our bases, we still recommend running a clean reinstall of the app on the affected devices.
All devices (4!) suddenly face this problem after updating. At least this time, usually the problem occurs suddenly for a version of the app that is installed for weeks or months. It's in issue not only for me and my family but also for others as you can read in the comments. And if you read all the information I provided in previous posts you'll see that it occurs on clean and used installs. Instead of seriously investigating the issue at Spotify you put the burden again at the end user by a lazy recommendation to reinstall.
Regarding the Spotify app, there's currently a newer version available, so it'll be updated once you perform the clean reinstall. Let us know how it goes after that.
That doesn't work either at the moment. But probably it is going to work in a few days, like it did in the last few years.
If the issue persists, could you check if your devices' firmware is up to date?
The software and firmware of all our devices (phones/tablets/chromecasts) run the latest version (and are still be supported).
I repeat: This is an intermittent issue for years, where it suddenly stops working, sometimes on a single device, sometimes on all. This time it occurred immediately after updated the app though. Usually it starts working again in a day or days, without updating the app. So the issue is not solely in the app, usually the problem occurs suddenly for a version of the app that is installed for weeks or months.
IMHO it must be a combination of the app, Spotify's servers and/or Spotify's Chromecast API implementation.