Show Cue System

My Windows 10 laptop has only a HDMI output (video 2). Want all my visuals to go to the HDMI projector screen and all the audio to come out the headphone jack.
When a Cue contains just an audio track or an audio track with a slide show it works fine: All the audio comes out the headphone jack and the visuals goto the HDMI jack.

But when I play a video that has sound within it, both the visual and the audio goes out the HDMI jack.
I've tried changing the video audio output from 'Default' to 'Front' and changing 'Video Playback Library' to 'TVG' .
I've also tried selecting 'Force Enabling of speaker Assignments' .

As I'm new to SCS there is likely some simple option that I'm not selecting but I don't know what it might be. Any ideas?

With your HDMI projector connected, start SCS and go to Production Properties - Video Audio Devices. If you click on the 'Physical Device' drop-down list against 'Default' you should find the HDMI audio device listed. You need to select that device and then click 'Apply Device Changes'. You can save the changes either as a new device map or to the current device map.

In SCS 11.6 there will be a new 'device' available named 'Default Audio Device'. This will map to whatever device Windows has currently assigned as the default for audio output, so typically will switch from, say, headphone jack to HDMI output when the HDMI device is connected.