Saving getCursor() to variable

Hello,
I'm trying to save the cursor from the InventoryClickEvent when the player clicks on a specific slot in a custom inventory.
While using getCurrentItem() would appear to make more sense here, I actually want a "live update" and getCurrentItem() is only called after another click, unlike getCursor(). I want to use the two variables to build a new item from the given type (either the first or second slot).
I started by initializing the two variables before the event is called:

Code:

    public ItemStack olditemtype3 = new ItemStack(Material.AIR);
    public ItemStack olditemtype5 = new ItemStack(Material.AIR);

Then I'm checking if the player has clicked in the first specific slot:

Code:

if(event.getRawSlot() == 3) {
                    if(cursor.getType().equals(Material.AIR) == false) {
                        olditemtype3 = cursor;
                        System.out.println(olditemtype5 + " THIS IS 5");
                        System.out.println(olditemtype3.getType() + " in 3");
                    }
                }

Same goes for the other slot:

Code:

                else if(event.getRawSlot() == 5) {
                    if(cursor.getType().equals(Material.AIR) == false) {
                        System.out.println("sdgfhdrhwgtqehetkztjertd");
                        olditemtype5 = cursor;
                        System.out.println(olditemtype3 + " THIS IS 3");
                        System.out.println(olditemtype5.getType() + " in 5");
                    }
                }

(Note: First slot is the third slot in the inventory and the second slot is the fith slot in the inventory)
Now if I try and go through it slowly and look at the config messages, this happens:
1. I put an item into the first slot.

So far so good, makes perfectly sense. In the 5th slot there's AIR, because that's what it's initialized with and I haven't assigned it to something else yet.
2. I put an item into the second slot.
Now the ItemStackType (Material) in the first slot is AIR, however it still has all the meta information stored.
And the second slot works fine.
I also tried it the other way around and got the inverted result, what a surprise.

My question is, why the Material changes all of a sudden and if there's another way to store these information.

Btw: I would reassign both variables once the new item is created and I don't need the information (basically reset it)

 

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