Some 3rd party apps may experience problems during the Beta, since they are not fully compatible with the new version yet.
Some app developers have already released updates, so it is worth checking if it is available.
Of course, it could be that there is a problem with our software, but for that it is necessary for us to analyze the problem.
So it would be a great help if you could share an error report with us using Beta Feedback option in Samsung Members app!
If I turn on loudness normalisation in the app the distortion goes away. Even at full volume.
Also whether normalisation is on or off, the music plays normally via my galaxy buds