What exactly do you mean by "at the same time"? Had 2 groups of 4 solving the puzzle and completed the 2nd line of each pylon within seconds of each other. Still bugged out. Do we need to alternate each console use between the 2 pylons?
You may also need the same person to use the console each time. We had the same person use each one until the 4th one, when we started using otehr people, and it worked. And solve the first one at the same time as well. Worked for us.