[Not a bug]Momentom ms dmg bug

Good day just wna clarify … The max ms for char is 50% …at first i uses 2x 15ms 1x 10ms +20 dex(hero skill) = 50 ms … 2nd i tried 3x 15ms + 20 dex = 55 ms … The dmg in stat still inc even i already reach the ms cap … I trued 4x 15ms +20 dex = 70ms an overwhelming dmg add to my stat again … Is this how it realy work? Or the ad dmg via overcap ms is abug?

If you have Momentum set equipped, the max cap for movespeed becomes 100%