Hamburger close bug

Hello guys!
I have a bug on the site I’m working on that I can’t understand. When I use the view on smaller screen sizes, the navigation menu becomes the “standard menu” with the “Full Screen Menu” style. So far so good. The problem arises when I click on the “X” button to close, since instead of returning to the normal view with the “standard menu” the navigation buttons also appear. Can anyone know what’s going on? Thank you for your attention.