Steps to Reproduce:

1. Tame a horse and equip it with a saddle
2. Equip elytra
3. Mount the horse
4. Reload the world
5. Press or hold the jump button

Observed Results:
The player starts gliding with the elytra.

Expected Results:
The player should not start gliding with the elytra.

Original Description:
I sink into the horse/get into a flying position when I try to get the horse to jump. This bug happens after I join my world after leaving it while sitting on a horse. My elytra is on.

I have a screen recording of this bug attached below.