You don't have any special rule on you, like teleport bullets or anything. But probably on the recording, you don't have that.
So at the ninja part, you shoot one bullet, pick up the ninja effect immediately and try to perform a dash, but the dash won't go off.
Reason being: The gun has a short delay of 0.1 or 0.2 seconds~. The ninja has at least a second long cooldown, before using it again.
When got the ninja effect, the cooldown switched from the gun's cooldown -> onto the ninja's cooldown.