2nd volta playing after 3rd volta instead of the 4th volta playing?

I've been trying to get these repeats to work using voltas, but instead of playing the 4th ending after the 3rd, it plays the 2nd? Any clue as to why this happens and how to fix it? Thanks for any help. (This arrangement is based off of this synthesia arrangement by Jon Pumper on YouTube btw, I didn't write it https://youtu.be/dX4_07WQqsU )