Hello,
Add the following code to child theme syle.css to remove opacity
.et-mini-content .menu li a:hover, div.mobile-menu-content .et_b_header-menu .menu li > .nav-sublist-dropdown:not(.nav-sublist), div.mobile-menu-content .et_b_header-menu .menu li > .nav-sublist > ul { opacity: 1; }
Regards
