Just a quick write-up until I can get the final version polished. Here’s how to enable HDMI audio output while your Samsung Galaxy S8/S8+ is docked in Samsung’s Dex dock and connected to a monitor or TV that supports HDMI audio. By default, audio will only come from the phone’s speaker while docked.
1. Click on the Applications icon in the lower left corner of the screen
2. Launch Samsung Connect
3. Within Samsung Connect, click the three dots in the upper right and choose Settings
4. Ensure Samsung Connect panel is enabled (slider) and then click the text of that option for more options
5. Ensure that the slider next to “Audio Output” is enabled, you can then close Samsung Connect
6. From the Dex desktop choose the “Quick Settings” icon in the system tray area (looks like a solid up arrow)
7. Click Audio Output under “Samsung Connect”
8. Change from “My Phone” to “Display Device”
That’s it. Audio should now come from your HDMI display.