I'm currently having the same problem, and clearing caches, and doesn't work. I'm currently on version 76.0.3809.136, and the model I'm using is the Acer c720. The problem started about 3-4 weeks ago and it hasn't been fixed since.
Some school chromebooks have limitations set by the system administrator that disrupt services like Spotify. There might be certain networking ports blocked, which are essential to the functionality of the Spotify service.
We'd recommend you reach out to the school system administrator for more info on this, as there might be some recent changes to their policy/ firewall which cause the issue with the Spotify stream.
Don't hesitate to reach out again if you have questions.
Help others find this answer and click "Accept as Solution".
If you appreciate my answer, maybe give me a Like.
“With freedom, flowers, books, and the moon, who could not be perfectly happy?” ― Oscar Wilde