I have achieved hearing the input audio on my hifiberry dsp board under libreelec on pi3b without any tweaks at all - works perfectly.
I am trying to do the same with a hifiberry I/O board on a pi4, but so far with no luck. The sound from libreelec itself is being heard, but not the sound sent to the input of the board.
Libreelec has two profiles for the board in the audio settings, neither of them do the trick.
Thanks in advance!