Conditional seekbar not allowing scroll when returning to slide

I'm putting together some legally mandated training and learners are required to watch every slide in entirety before they can advance.

I'd like to set up my course using the conditional seekbar so that the learner can scrub through the timeline when they come back to the slide later. At the moment, activating the conditional seekbar allows them to scrub after the slide has completed but before advancing. If they hit the back button from the next slide, then they are forced to watch the entire slide again. 

Is there anything that will allow me to do this? I don't see any way to control this using triggers.