I'm a total newb. And I'm trying to make a room in a dungeon where when you step in and through a trigger box, some gate poles will come up and block your way back, and stay up until you press a nearby button. This seems really simple in theory, but I can't for the life of me figure out how to do it.

I've already figured out buttons/levers for doors and triggers for ambushes. The same trigger box I'm trying to use already successfully triggers an ambush, so the trigger box itself seems to be working. I can get the poles to connect to a trigger and lower themselves down, but no matter what I do, I can't make them start as hidden and then come up. No matter what combination of settings I try, they either start out as already up and blocking your way, or they're hidden but don't ever pop up. Even when I just connect them to an actual lever, if I manage to get them to start as lowered beneath the floor, they just won't come up no matter how many times I pull the lever.

I mean it seems like it should be pretty simple, but obviously I'm missing something vital here.