When you press the space bar while flying with an elytra in creative mode, you will fly upwards. 

What I expected to happen:

I would stay in frame while flying upwards with an elytra.

What happened: 

When I went to 3rd person mode, and moved the mouse around while flying upwards with an elytra, the character randomly appeared and disappeared. The figure in the top left corner also started rapidly glitching.

 Steps to Reproduce:

1. Go to creative mode
2. Equip an elytra
3. Start flying
4. Press and hold the space bar
5. Still holding the space bar, press f5 twice and move your mouse around rapidly

The character should rapidly appear and disappear