HTPC Windows 10 to AV Receiver and DSD question

Im trying Roon at the last days and I have one question to DSD files playing over the following chain: Win 10 --> HDMI --> Pioneer SC LX-56.

I have a fresh Windows installation withe the latest BIOS and drivers. Roon server runs on that machine.

WASAPI Exclusive mode is playing fine for all files except DSD64/DSF files. Nothing of the three settings seems to work. DSD is not playing natively over HDMI, DSD is not playing DoP over HDMI and DSD will not be converted to PCM. By the first two settings I have no sound at my speakers. The last setting let the speakers sound like a machine gun.

DSD to PCM over Airplay is playing fine, why is DSD to PCM over HDMI faulty? The signal chain in Roon shows no conversion.

Enno