Hi LHornet,
Are you able to play other audio on this iPad such as music or a YouTube video, or even another Facebook video?
If so, it may be an issue with that specific persons live stream. We can recommend deleting the Facebook and reinstalling it. While the steps here are for if an app won't open or closes unexpectedly, they'd also work to isolate this issue with Facebook.
"If an app on your iPhone or iPad doesn't work as expected, try this.
Close and reopen the app
Force the app to close. Then open the app to see if it works as expected.
Restart your device
Restart your iPhone or restart your iPad. Then open the app to see if it works as expected.
Check for updates
To see if updates are available for the app, open the App Store, tap your profile icon, then scroll down to see if updates are available. If updates aren't available for the app, update the software on your iPhone or iPad.
Delete the app, then redownload it
Delete the app. When you do this, you might lose data that was stored in the app. Then redownload the app. Then check to see if the problem with the app is fixed."
For assistance beyond that, we'd recommend either contacting that specific person if you are able, or Facebook for more assistance.
Cheers!