Hi AppleMusicClassicBug,
For help with the AirPlay icon image, have you tried a normal restart of your iPhone? If not, test the steps below found in the article here: Restart your iPad - Apple Support
"How to restart an iPad without a Home button
- Press and hold either volume button and the top button until the power off slider appears.
2. Drag the slider, then wait 30 seconds for your device to turn off. If your device is frozen or unresponsive, force restart your device.
3. To turn your device back on, press and hold the top button until you see the Apple logo."
If the issue continues, as the icon should show rounded as outlined in the article here: How to share time-synced lyrics in the Apple Music app on your iPhone or iPad if Apple Music is the only app this occurs with feel free to leave a bug report here: Product Feedback - Apple
For further assistance and to report the issue you can also reach out to Apple Support directly. The links below will help you get connected.
Contact - Official Apple Support
Contact Apple for support and service - Apple Support
Best.