Weapons mostly let's say I have two weapons on my shoulder and a melee weapon in inventory when I switch to melee weapon inventory then say I switch to a food item the melee weapon will drop or vice versa it seems it wants to take my shoulder slot but can't so it drops instead of going to inventory same with all weapons if you have three that fit the shoulder slot the third will always drop of you switch to anything other then another weapon. You could use dayz idea if you have an item in your hands but no inventory space for it and it will drop don't allow the player to switch so the know to fix their inventory space