I do not differentiate between pro/non-pro for support requests (mostly I don't even have that information). That said, I am getting *way* too many emails to be able to respond to all of them while still finding the time to actually work on the app.
The notification sounds are a system setting since Android 8.0 and my app has only control over it when it is first installed (or reinstalled).
To check if your settings are correct, in the Deliveries app go to "Settings -> Notifications -> More options" and make sure that the "Statuses" category has a valid notification sound and the style is either "Sound" or "Sound with popup".