I recently built a HTPC with Kaby Lake Core i5, Windows 10 (1809). I also installed the Dolby Atmos App from the Windows App Store, everything worked fine (all components connected via HDMI).
Today I've updated the graphics driver to DCH. Unfortunately now the option to enable Dolby Atmos in Windows is gone, the setup tool (Dolby Access) can't detect support for Dolby Atmos. Already re-installed the app without success. I also see my receiver shows Stereo only, not even 5.1 or 7.1 is coming up.
Is this issue known?
Good news, the issue has been resolved. Today I've looked on the Dolby website and found an article which was related to Windows 10 version 1809. Dolby Access needed an update to work properly but i couldn't find an option to update. It said Dolby Access should update automatically so i tried again and magically Dolby Atmos for Home Theater was available again. I assume when moving to Windows 10 the Dolby Atmos support was gone already which I didn't recognize immediately. So nothing related to the DCH driver but to Windows updates. Netflix also showed Dolby Atmos support again, everything seems to work fine again.