At the Start of the run in the Museum, I've seen the top runs jump over the handrail to get down from the top floor, halfway though the stage but I cant seem to get it to work with the latest patch. is it a Patch Specific thing? cause i have noticed in the patch notes of the game, there were some fixes to the level.

It works in the latest patch. You need to walk parallel with the railing for it to work.