Take a stack of five feathers and a stack of five sharpened sticks. Dragging the feathers over the sticks is resulting in a stack with 5 arrows but only one feather is used, four are left.
When loading the bow with this 5-arrow-stack your "magazine" is invisible.
Now when you are shooting on a tree, all five arrows are fired at the same time.
Stuck in the tree they are not visible in the UI when you're standing in front of them.
Take them by focussing with the crosshair, you get the stack back, but the problem remains.
Rearanging the stack with "split" and "combine" makes things more worse.