I found out by accident that you can't drop items with open inventory when you hold the Gui opener in main hand if you in survival mode.
It just didn't drop it or even delete the item.

After some testing i found no solution for this problem so i made it only aviable for extendedcrafting.op permission and deleted the Vanilla Recipe (also settings for this).

I guess users won't use the command as much as an operator would.

Hope you still enjoy it and don't forget to let me know what you think about it