The point of test with new NAA OS 4.2.3 is to try latest kernel v5.15 because this new kernel had some significant changes
The NAA OS test I mentioned in 2021 was using old v5.4 and was expected to fail back then (but he tried it anyway)
So there was a reason I suggested trying new NAA OS - thats why I was hoping you had an Intel laptop around. Remember I mentioned it is better not to have to buy anything 
The old NAA OS 2021 experiment was expected to fail. And there was a technical reason to try new NAA OS. Unfortunately didn’t work for you
But something is strange because DoP should work with NAA OS if macOS NAA works
Try DAC bits = default? I can’t think of anything else
Also try this sequence. Quit HQPLayer app and power off RPi4 and DAC
- Turn on DAC
- Boot RPi4 NAA OS - wait 1 minute to fully load
- Open HQPLayer Desktop last
Then try to play music