Video Cuepoints won't trigger nested slides

I have built a slide presentation based on the Darwin tutorial. Works very well. I am attempting to add additional text layers to my slides by adding child screens, which I can see on the stage when I select the child screens. I’ve added additional cue points to trigger the child slides.

Problem: The cue points aren’t triggering the appearance of the child slides (at run time).

The child slides trigger properly if I move them “up” a level (first child level below the parent).

Any help would be great.