DTS-HD passthrough not working

Hi,

I am using Windows 10 and Kodi 17.1
I have a HTPC connected with HDMI to my Samsung HT-D6750W receiver that supports DTS-HD according to the manual.
I have set up audio to use WASAPI for normal and passthrough.
When I enable DTS-HD to passthrough I do not have any sound when playing a video containing DTS-HD audio.

Does anyone have an idea why this is?
Does it matter if I don’t use passthrough for this? Because I do hear surround sound when disabling it. My guess is that Kodi itself will decode the DTS-HD before sending it to the receiver. Although this might unncesesarily strain my weak CPU in the HTPC. So if I could get the passthrough working that would be cool.
The DTS passthrough does work with no problem.