When Buttpack is on the ground in vicinity or in my hands, pressing triangle places it in my backpack slot. This happens even when I have a pristine assault vest equipped.

I can hold X button to drag it to the equipment slot, however when equipped I cannot remove anything from it unless I place the buttpack in my hands or on the floor.

Also, when equipped, it bugs my entire inventory tabs. For example, I cannot simply scroll down from top to bottom in the items. It seems to jump at random. And there seem to be invisible walls within my inventory where I cannot scroll past a certain point. I need to drop clothing items to actually navigate my inventory space.