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:
Place some doors and trapdoors.
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.
Glass panes do as well