Actually version 1.16.210

What I expected to happen was...:
When gliding using Elytra, Firework should fire and sustain flight.

What actually happened was...

   Firework fired initially, gained some altitude, but subsequent Fireworks failed. Fell to ground repeatedly.

Steps to Reproduce:
1. Put on Elytra
2. ...Glide
3. ...Fire Firework to gain altitude

4... Fire second Firework. Second or third or fourth firework fails (and all subsequent fireworks while airborn) resulting in plummet to ground.