any idea why this is happening?

https://reddit.com/link/1u4x40s/video/mhjkx1o1637h1/player

im wondering because im trying to make a race stambecco (if the pigeon gets a race config they all should) as far as im concerned its not a heat related issue. but i dont know. i know its also not a overrev issue as i got the performance 2 block in it.