I think I've found a bug, when I delete a gate that I used in another gate, it deletes both of them and it will show forever in that project the Inputs and Outputs that were in the gate, the only way to "remove" them is opening another project.
Can you add that when you are deleting a gate you first need to accept it or a button that allows you to return back in actions? it happened me today that i somehow deleted all of my gates in the project. Thank you :)