Character model and camera collision with the non-moving parts of a Trick Bookshelf Partition are completely disabled, if the secret door is already open when you enter the housing instance where it is located.
Date & Time: Whenever the steps below are followed
Frequency: See above
World name: Cactuar
Character name: Bratomil Jionisch
Housing: Supposedly consistent across every housing instance. Tested and confirmed in the instances below:
• The Lavender Beds, 10th Ward, Plot 10
• The Lavender Beds, 10th Ward, Lily Hills, Apartment 10
• The Goblet, 2nd Ward, Plot 19
• The Goblet, 2nd Ward, Plot 19, Private Chamber 2
• The Goblet, 5th Ward, Plot 60
Steps:
1. Place a Trick Bookshelf Partition in a housing instance.
2. Exit the furnishing placement interface.
3. Observe and confirm that both the camera and your character model collide with the furnishing, except in the area where the secret door is positioned.
4. Find a way to keep the secret door open. This can be done by positioning a mannequin or NPC near the Trick Bookshelf Partition, or by asking another player to stand next to it while the test is performed.
5. Leave and reenter the housing instance. Due to the mannequin, NPC or player character standing nearby, the secret door in the Trick Bookshelf Partition will open as soon as you load in the area.
6. Observe that both the camera and your character model will now completely bypass collision checks with the Trick Bookshelf Partition in its entirety, rather than just in the area where the secret door is located.
Moving the mannequin, NPC or player character away from the Trick Bookshelf Partition restores the collision until steps 4 and 5 are performed again. The bug affects every character, and not just owners and tenants.
I have also been able to reproduce the bug, under the same circumstances and by following the same steps, with the items Glade Partition Door and Mahogany Partition Door. The only difference is that these two items, normally, only have character model collision and no camera collision. When following the steps above, the character model collision ceases to work.