I just checked the Oppo, It has HDMI Output settings: Auto, Bitstream, and LPCM. I tried them all, no luck. LPCM is set to 192K
I have a old Yamaha RX-V 520 AV Receiver and if I plug the HTPC in via digital coax and play a 96k file, it shows on the front display 96K Stereo, I am sure the HTPC is outputting properly, The same with the OPPO, If plugged into the Yamaha, it will Show 96K Stereo or if I use a 192K file it will show "Unknown" as it does not do 192K, but it still plays the file. I believe the issue is with the Pioneer, but I have checked every setting in it that I can find, no luck. It's odd that the Pioneer will display 192K Stereo when switched to an unused Digital Coax input.