It flies straight up and much less higher compared to fired by hand. In 1.14.4 after a certain amount of flight it would disperse to a random side, just like when shot by hand. Atm it just goes straight up and noticeably less higher than before. I had a commandblock fireworkshow that after the update is just broken. They don’t go as high (like it’s hilariously low compared to 1.14 or shot by hand) and they don’t disperse.
That being said, this issue is not resolved.