I don’t think this setup is going to work. Basically you have an Event Tick which runs every frame, while the two events, Pickup and Drop, from the interface which are supposed to Open/Close the gate run only when invoked by the Motion Controllers.
If you really need to work with an Event Tick, the right approach would be to have Pickup and Drop event to independently set a Boolean variable and the check this variable during the Event Tick.
Not easy to comment further since you are not showing the whole Blueprint.