help: procedure to have chicken spawn a firework_rocket

So I made a custom living entity, which is basically a chicken, and I have a trigger for a procedure when player right clicks on the entity. The procedure executes, but not as expected.

My expectation is a rocket fires up from the chicken and bursts in the sky, just as if a player or summon command does.

What actually happens is a bit of smoke particles comes from underneath the chicken, the firework launch sounds is heard, but no trail particles, and no visual burst, and no burst sound. SO while the procedure does successfully run on rightclick, I'm struggling to get a firework_rocket to launch out of my chicken (lol).

This is my procedure:

and the command is:

summon firework_rocket ~ ~ ~ {LifeTime:15,FireworksItem:{id:firework_rocket,Count:1,tag:{Fireworks:{Explosions:[{Type:4,Flicker:1b,Trail:1b,Colors:[I;1376044],FadeColors:[I;16711680]}]}}}}

and if I type that exact command in the in-game console, a firework rocket spawns. launches, leaves trails, and bursts as expected.

Other things I tried: using a procedure that does "spawn at x y z with yaw pitch vx vy vz entity FIrework rocket" ... also tried command "execute as @e[asdasdas] run summon etc"

It's almost as the entity that is the firework rocket is trapped inside the chicken hitbox and can't leave it.

Any ideas?!