As of October 5 2021, Facebook has stopped allowing login authentication within embedded browsers. This means when trying to authenticate with Spotify using the Facebook option, you're presented with an error message. (https://developers.facebook.com/blog/post/2021/06/28/deprecating-support-fb-login-authentication-android-embedded-browsers)

The Android Spotify SDK has been updated to fix this issue (it now uses a custom tab instead of a webview): https://github.com/spotify/android-sdk/tree/master/auth-lib