The bug

When killed while having the nausea effect on you, when respawning a nether portal animation can be seen on screen.

How to reproduce

1. Get the nausea effect either by eating a pufferfish or by running the command

/effect give @p minecraft:nausea

2. Get yourself killed or run the command

/kill

3. Respawn 

Observed result

A nether portal animation is seen on screen.

Expected result

No nether portal animation should be seen.