Are you using a laptop or desktop PC? You can try taking the HDMI cable from the HMD and bypassing the link box by connecting it directly into the video card. Don't bypass USB or anything else.
The 3DSP mentions ambisonics in the documentation, but is it handled the same way that SteamAudio handles ambisonic files? Do we use the C API like in Steam Audio? I couldn't find anything on how it handles multi-channel audio.