Audio Playback LPCM multichannel tracks

[FrankD]

I have loaded a couple of music blu rays with lpcm multichannel audio tracks.
Only the left and right channels are outputting sound. This bug does need a fix.

Multichannel from TrueHD and DTS Master are playing over all channels.

[signals]

How are you supplying the audio to the sound system (HDMI, optical....)? Try setting the audio to Passthrough if your sound system device will decode LPCM.

[FrankD]

I'm using HDMI passthrough and lpcm option is checked in the receiver compatibility list.
Also tried passthrough 'off' and 'auto' options but that makes no difference.
LPCM stereo track plays fine. Only the front L&R channels play with the multichannel tracks the center and rears are silent.

The MS is attached an HDMI input at the back of an Oppo UDP203 UHD player.