Yes, I know there's a KMPlayer forum, and I've actually posted my question there...
But I'm getting a feeling that their TS is taking a long break!

This only happen with TrueHD track, have not yet tested with DTS HD-MA.
* LAV Audio and Splitter are used!

With latest KMP4, I got this Null Audio Codec in the filter list, which causes no signal output to amplifier.
Null Audio codec?

With old KMP, the internal KMP Audio kicked in, even I disabled all internal audio codec... I have forced use the LAV audio filter in external filter manager. I have exact problem as the linked thread, but the trick doesn't work for me.
Disable internal TrueHD Decoder

I'm guessing some specific setting(s) in preference might help, but I'm out of idea atm and trial and error is really tiring