Well, a single play audio only motion is not common. The "simple" feature is to place a loop after the video/audio motion menu "intro" plays once. But the menu to menu option is "simpler."
Try it the other way. If you did what I described, use your menu 1 only. Remove its end action and set that to loop forever. Set the menu/motion duration to several seconds longer than your audio and place the loop point at a second over the length.