Muzzle flash particle firing both sides

Hi, I created a muzzle flash particle effect for a gun and got it firing on the gun animation. The problem is, it randomly flips direction each time it fires, as in it is firing either towards the player (not the intended direction) or away from the player (as required). I have no idea what is causing this flipping. I have the same particle on a different skeletal mesh and it is not flipping on that. I don’t know what the problem is. Can anyone please help?