Dispenser ignoring flight nbt

Hello,

In 1.15.1, when shooting fireworks from a dispenser, it ignores nbt tags.
Example.

replaceitem block ~-2 ~-1 ~3 container.1 firework_rocket{Fireworks:{Flight:5,Explosions:[

{Type:1,Flicker:1,Trail:1,Colors:[I;8073150,6719955,12801229],FadeColors:[I;14188952,4312372]}

,

{Type:2,Flicker:0,Trail:0,Colors:[I;4312372],FadeColors:[I;14188952]}

]}} 2

 

in a command block, shoot dispenser, dispenser ignores flight nbt tags.

If you take it out of the dispenser or spawn it with a command like /give, it works properly.

This also worked fine in 1.14.4, but is broken in 1.15.1 ?