iOS 13 Beta (Only) on any iOS device is causing an issue with Infinite Flight to lose all sounds after an ATC message is transmitted. There is NO FIX to the issue as of now. Not even restarting, or reinstalling IF. You are stuck.
What to do if you want to go back to iOS 12.4:
It is not very simple to go back to a stable version of iOS like iOS 12.4. If you do wish to revert back to the stable iOS 12.4, you will need to have a back up of your device from when your device was running iOS 12.4 (if you don’t, just don’t even try. It won’t work, you might just lose everything). If you do have an iOS 12.4 back up, you will need to download the iOS 12.4 IPSW from a website, then go to iTunes and restore the device with that IPSW first (there are many tutorials out there to help you with that process). Once on iOS 12.4, restore your device with the iOS 12.4 back up.
If you are fine with the issue for now:
iOS 13 Beta 6 will be released in about a week or two and the issue might be fixed as I believe that the issue is related to the new 32 point volume instead of the old 16 point volume. The stable version of iOS 13 will be released alongside the new iPhone in September, so till then, deleting the beta profile will not help. Please make sure that in September, you delete the iOS Beta Profile to stop receiving further Beta firmwares in the future.
iOS 13 Beta 6 Update:
iOS 13 Beta 6 was released as a developers’ update and the issue remains.