/replaceitem is not working when giving yourself fireworks. /give works fine but replaceitem is bugged. it should be giving you flight duration 1 rockets, but with replaceitem it gives you rockets with no flight duration. meaning they cant be fired properly from a crossbow. its really confusing because /give @s firework_rocket works just fine. also I should mention that there are two firework rocket options "fireworks" and "firework_rocket" I've tried both of them neither work but both of them work with give.