are they facing each other? If you are familiar with the editor you could open the map and select the region named "Swann enter hyperion 1" double click it and select shape. Then select circle and change the size to be bigger. Do this also for "John enter hyperion 1"
This may make the scene look strange, but at least you could move forward in the cinematic.
EDIT: Also make sure you have the latest update of your editor and Starcraft 2 copy. Though I doubt that is an issue here. And have you made it as far as the image in dialogue.
I´ m using the Ai module and never had a problem with it before. In one of my map, the last two or three waves moves up to the players base and waits outside and won t attack. The target point and gather point has not changed and all the other waves work fine, it´ s just the last ones that won´t work.