i have installed the demo but there is no sound when pressing the midi piano keys,
there is a sound when i press on the virtual keyboard with my mouse,
and when pressing on the midi piano i can see the virtual keys being pressed but without sound.
things i tried:
change channel to omni,
set midi input to A as it was off by default,
set sound output as it was off by default,
reinstall the app,
restore the midi piano to factory settings,
i did everything i found online, with no change