Player nametags reduce in opacity when flying downwards in creative mode

The Bug:

Player nametags reduce in opacity when flying downwards in creative mode.

Steps to Reproduce:

1. Get a player to enter creative mode and have them start flying up and down constantly.
2. Look closely at their nametag as they fly downwards.
3. Take note as to whether or not player nametags reduce in opacity when flying downwards in creative mode.

Observed Behavior:

Player nametags reduce in opacity.

Expected Behavior:

Player nametags would not reduce in opacity. Their player model doesn't appear to be sneaking, so their nametag should not reduce in opacity.