Hamburger mobile menu square box problem

[DeeJaYxxx]

I'm new here, so Hi Guys
I have a problem with mobile menu on my website. When I click the hamburger icon, appears menu and the icon is with square box. Please check photo. Can somebody tell me, how to fix (hide) it?

Thanks in advance!

 

[DeeJaYxxx]

The problem is solved.
I just insert the below custom CSS into nav menu widget's custom CSS section:

.elementor *, .elementor :after, .elementor :before {
outline: none !important;
box-shadow: none !important;
}