Marker won't close when another marker is selected.

I played around with the file. I think even adding visited states to the markers with audio may cause the marker to not play properly.

• I'd use the markers with no added states. 
• You need a way to track what's been visited. I'd add a trigger to change the state of the background oval to visited when the marker is clicked.
• Then modify your jump to slide trigger to do that when the state of the ovals are all visited.

One other thing to consider is that when the last marker is selected it will jump without the person hearing the audio, so I'd lock navigation or have a hidden button that appears when all are visited. This way they don't leave the slide until the click to leave.

Personally, I'd build the interaction using layers and not the markers. It gives you more control over what's happening and less dependent on the pre-built nature of the markers.