Hello andreaaaaaaaaaa,
There are a few steps we can try to get your music working as expected on your Android phone.
First, close the Music app on your phone.
If you see a message that says "If you force stop an app, it may misbehave," tap OK.
Return to the Home screen or the application list, and reopen Apple Music.
This page has some information about Apple Music for Android, which goes over the steps to use Chromecast.
Use Apple Music with your Android devices - Apple Support
Stream music from Apple Music to your Chromecast device
1. Make sure that your Android device and Chromecast device are connected to the same Wi-Fi network.
2. Open the Apple Music app.
3. At the top of your screen, tap the Cast button
.

4. Tap your Chromecast device.
5. Play music.
If you need help with your Chromecast, visit Google Support.
• Not all content types in Apple Music support Casting, and not all Chromecast devices are supported.
If songs are still not playing for longer than 15 mins, check with Google Support, using the link above.
If advised that songs over 15 mins are compatible with your device, next is to contact Apple Support for additional assistance.
Apple Support
Thank you for using Apple Support Communities.
Take care!