Inventories on crates/trunks/bags may not sync properly at times. This can cause issues when trying to store items with teammates inside of car trunks, chests, etc. This also is the same for when items are dropped for teammates. This doesn't happen all of the time but it has happened frequent enough to become a problem, especially when trying to help teammates heal or store items in chests/etc.
Items can also be invisible for others when this "desync" occurs. For example, a friend had a jerry can in their hands and it was invisible to me. Also, when they tried to drop the can for me, I could not see it nor interact with it. This happens with all items and does not matter that the type of item it is.
This also happens when items can be seen by other players as well. For example, I can see my friend has a long stick in their hands, but when they drop it, it still shows in their hands or disappears and I can not pick it up. This is not limited to any specific item. Happened to multiple teammates. Usually restarting the game fixes it but there have been a few times where restarting the game did not fix the issue.
When inventories aren't syncing properly, incorrect items are shown as stored in trunks, chests, bags, etc. For example, if I remove something from a chest, some teammates will still see the item in the chest but wont be able to remove it and the chest will show the item still taking up inventory slots inside of that container. Not limited to any certain type of container.