The specific tablet menu in question is this one.
The tablet menu opens on 1st click when you click on the icon the very first time.
But after that, the tablet menu only opens on the 2nd click.
We used the same navbar layering and animation on another page called Next Episode. The tablet menu for that page works no problem. We checked all the z-index for the navbar elements between the 2 pages, and they are all the same. They also use the same tablet menu animation to open the menu.
We are incredibly puzzled still, despite trying to figure this out for days! Would anyone be able to provide a fresh second eye and look into this please?