Need help on 95 set up as HDMI transport

Hi all,
I currently have NAD M51 DAC and hook up to Oppo 95 as HDMI transport. The M51 lock in when Oppo play RBCD but unlock when play SACD. I also have hi-rez files play from external HD, and still cannot lock in the HDMI signal.
I set up Oppo based on instruction from the manual (page 61)
HDMI Audio set as Auto, LPCM, Bitstream - the DAC still not lock in
SACD Output also set as PCM did not help on play SACD

If you successfully set up Oppo 95/93 as HDMI digital output to your DAC, please post your set up here
Thanks for your help
Best regards
Have you tried setting the Oppo preferences to stereo or selecting the stereo track from SACD? Otherwise, choosing LPCM for output and PCM for SACD output is correct.
I figured out that in the video set up, somehow the HDMI was set as no audio. Change this setting enable audio to pipe thru HDMI. All good now