Ok i see many things
First i think if i understand well what you want to do that you should do that
Next if you nav menu doest appear i guess its because you replaced the initial burger of the WF navbar with a custom one.
It's a good idea but since i have no idea how the WF navbar works i can't really help you but i think its probably what is causing you problem. Maybe @Waldo can confirm this
Right now in your interaction you don't say to the burger to open the menu via affect another element you just tell it to do the animation.
If i were you
I would build a custom navbar, using a simple div for
Nav-menu and using interaction between this div and your burger. You are not far from that right now.