Just bought a Q5 Pro, and confirm the bug: no Audio with DTS-HD High Resolution tracks.

DTS-HD Master Audio and DTS:X tracks work without a problem (just like Dolby Digital Plus, Dolby True HD and Dolby Atmos).
This is not a AV-Receiver / HDMI issue. The HR tracks play fine from an old NeoTV 550 (2011 btw), from the PC, or from the Blu-ray disc player.
There are lot of releases with High Resolution audio tracks. This should get fixed ASAP !!!