Davinci an Dolby Atmos

First attempt with Dolby Atmos and Davinci 18.0 beta (last update).
I open the System tab in the Davinci Resolve > Preferences menu and select the Video and Audio IO page. I use the Headphone Astro A50 Games. This audio system has 8 channels. In the Monitor Speaker Configuration area, I first set the profile to stereo. I select a WAV file in Davinci's Working Area Media. It plays and I can hear it. I switch back to the Monitor Speaker Configuration and select the format 5.1. I assign all channels of the IO engine to the layout. Now I play the same WAV file and no sound is emitted. However, all other attempts are no longer useful, because a simple output of a sound file in a format larger than stereo does not work. Where the error lies is not relevant to me. The Dolby Atmos function with more than two channels does not work in the program.
I hope that I was able to describe my problem as well as possible.
What can I do?
Thanks again in advance.

There is a special form for version 18 issues.

viewforum.php?f=36

Hi,
I have found an important context that I would like to share. I use the ASTRO A50 Wireless headset. With the installation of the Command Centers, drivers for a surround sound are installed. There are three options, no surround sound, Windows Sonic and Dolby Atmos. When I activate Dolby Atmos, the headset can only use a stereo profile for channel mapping. When I use Windows Sonic, I can use all 8 channels. I can then, as expected, attach a sound source to each channel and identify it. This might be the mistake in Davinci that only a stereo profile for the headphones works in a Dolby Atmos surround sound.
So a driver problem from Dolby Atmos?