Quadmenu is breaking Customizer

Hi there,
Quadmenu is breaking the core WordPress Customiser. Upon disabling, it works fine again, but I really need to have Quadmenu working for this project.

I was originally getting an Internal Server Error 500, but now simply just a white screen.

I’m using Astra Pro with the Quadmenu Astra extension plugin.

The page I need help with: [log in to see the link]