Hi there,
some of the Elementor theme styles are being applied to ALL buttons which is also affecting the menu toggle.
You can use some CSS to overwrite that:
/* Mobile menu button */
.mobile-menu-control-wrapper .menu-toggle {
background-color: transparent;
border-color: transparent;
color: #000;
}
/* Hover color */
.mobile-menu-control-wrapper .menu-toggle:hover {
background-color: transparent;
border-color: transparent;
color: #000;
}
Change the colors to suit