Creating a mission with the editor I added an item to a backpack on the ground.
In-game the backpack was invisible but could still be picked up and became visible when on the player and accessible via the I Inventory.
I then board any vehicle and the backpack is left neatly on the ground standing upright instead of on its side.
Getting out of the vehicle returns the backpack to the player but it sometimes flickers.
{F20407}Place backpack on the ground.
Add an item to the backpack.
In-game pick-up the backpack.
Get in a vehicle.
I was using this piece of script in the backpacks Init field 'addWeapon ;hgun_Rook40_F'
Mass closing ancient tickets with no activity for > 12 months; assume fixed or too trivial.
If this issue is still relevant in current dev build, please re-post.
Also note that setting a ticket to private is not the best idea, because hardly anyone will see it.