I to am experiencing the Apple music casting function failure aswell. This app has worked flawlessly for years. As of Feb. 7 2022 it started displaying a screen that is stating "this device is not currently supported" while skipping through all the songs in my library. I called Apple support and spoke to three separate technical support agents for over 2 hours. The issue is still unresolved. All other streaming apps work fine on my phone. Very disappointed in Apple