Issue with interaction of element with backdrop filter

Dear community,

I’ve stumbled upon an issue with setting up the opening and closing of the menu for the website I’m currently working on.
I have a custom embed code “Global CSS” on the project that defines that the menu has a backdrop filter, and I think that that is making the animation/interaction with the button not work. Might it be a bug or am I doing something wrong?

Here is my public share link: Webflow - Octagon Blues