Whenever players (my friends and I) drop something onto the floor, those things dropped would not instantly appear on the floor. Instead, it will appear after a while (1-5 min) on the floor and players (my friends and I) would only be able to access those things at that time. Sometimes things got bugged and can never be found. This seems to appear more frequently inside buildings.
I got my cooking pot, gas stove and gas canister bugged once when I put them on the ground floor inside a 2-stories high orange house, and can never find them.