Doors and Trapdoors of all types do not render when viewed through Slimes. I found this bug while designing something in Creative mode and a slime passed in front of my work. I tested all trapdoors in the current version, then in the beta. The problem exists for both versions.

(the screenshot is in a world with beta features turned on)

Steps to Reproduce:

1. Place some doors and trapdoors.
2. Spawn a slime in front of them.

Observed Results:
The doors and trapdoors do not render through the slime.

Expected Results:
The doors and trapdoors should render through the slime.