Vybor military base, and possible other locations. Bags, and other items can disappear after a # of minutes.
I watched my high cap vests disappear 1 by one. I had 2 then re spawn latter on in the barracks at vybor military base with no items in them.
I carried my medical items in one, and ammo in the other. Both decided to go poof after a length of time.
Yet my items I threw onto the ground stayed.
Yet my blue backpack stayed.
Items left in the field can go poof as well its a random thing with most other items but when it comes to these high cap vests they tend to go poof after 10+ minutes.
I don't know if it was designed this way or not.