Lego loop coaster stuck at top after letting off the riders.

As you can see in the video the riders slide onto the track prolly like 7 out of 10 times and then it won’t come down. I have tried fidgeting with everything on I can to make it sure nothing is stuck or too tight. At one point it actually came down twice on its own and then immediately stopped doing that and all of a sudden needed to be pushed down again. The counter weight is in the right position it just won’t come down. Any help would be greatly appreciated. submitted by ...