Question about Quad Lock Fork Stem Mount

Officially it does not fit. The diameter of the tube under the nut with the hole is actually too large. When tightening, the lower mandrel of the fork stem mount is not pressed in tight enough because it does not hold. But my son still managed to hold it in place on the Ninja. He put the mandrel into the hole slightly tightened, just so that you can still press it in. Then it has grip and can be tightened until it is firmly in place. A bit of trial and error and keeping your nerve should do the trick.