I completed all the panels in the red bunker in the marsh and exited the other side. I solved the first panel and was lowered to the second. I solved the panel again, but was not standing in the proper place, so was taken back up. Is there a way to “reset” these panels, short of starting over? The panel no longer accepts the the solution to lower you. Or is there another way to access the walkway up the mountain to the laser?

try to solve the panel with different solutions. you don't really have to reset. you will get the secret behind it by yourself i believe.