Player sneaking animation is not showing when clipping through a block

The bug

When the player is at the same block/position as a closed door or trapdoor, and the player is inside of that door (clipping through it), upon sneaking / crouching, the sneak animation does not show up at all, even though the player is sneaking (the player's speed decreases, and becomes the same as the sneaking speed, therefore the player is sneaking).

To reproduce

1. Place a door
2. Open the door
3. Go stand at the position of that door, so when the door closes, you end up clipping through that door.
4. Close the door.
5. Attempt to sneak.
6. Move while sneaking.