When I tame a parrot and make it sit on the shoulder of the player. When the player is flying using a elytra and firework rockets the parrot will also fly with the elytra. When I move the mouse cursor down the stop flying with the player.

https://drive.google.com/file/d/18K3MylDas2_Lp3E02JRURSe9tjmmLGbN/view?usp=sharing