Amazingly, it works a little bit better on your page.
I have a higher chance to reach the lower level menu.
Can you maybe link it to one of the sub-menu 4,5 position deep in the nested menu?
How did you achieve to expand the fly-out without any action? this could be a acceptable workaround to leave all levels with child’s underneath without target.
e.g., I could add a second lower level entry for the context form.
Does it make any difference whether I link the menu entry to a WP page, category, fixed article etc?