[1.12] Larger Chest creates container a second time.

[EvilTwin]

When I open my chest (36 slots) ingame it first creates a container with 27 slots, and then overrides the first container with a second one with 36 slots. Nowhere in my code did I tell the container the number 27 in the first place, so where does this come from is there a method to stop this? 

This results in a bug, that results in the item that is in the last row of the chest, to also be placed inside of the players inventory. I don't really want code just food for thought

Thanks in advance

Edited December 20, 2017 by EvilTwin
version in title

[EvilTwin]

Nevermind I solved it, but thanks anyways