Dispensers in same setup - one does not dispense

Dispenser bug. Both dispsnesers receiving the same signal from a tripwire. Same setup, but only one dispenses. See video for a demonstration: https://youtu.be/OIkC6fCuP7E

 

Based on SethBling's video: https://www.youtube.com/watch?v=Fc2weXUNwh0