What would you do with an obstacle course that has 3 obstacles, but no one ever fails the first of the three?

So I had made an obstacle course online and people tried it on ROBLOX. In the first 4 competitions, less than 10 people in each competition got to stage 3. Every single one of those competitors in each competition cleared the first obstacle. In the fifth competition, I changed the course to be harder, so I changed the first obstacle of stage 3. It was more difficult, but out of 9 combined attempts so far, only one person has failed it (barely and at the end). Do massive changes need to be applied to the first obstacle, or give it one more chance?