Header broken after theme update

I am using Logo center menu below header with some minor custom CSS. I set the middle menu item as a Mega Menu with an image for the Navigation Label

This was working perfectly fine until this update from 4.0.5 to 4.1.2. I would like to know how to fix this so my menu has a white background again and isn’t overlapping the content.

/*Header*/
.html_header_transparency.header_bg {
opacity: 1 !important;
}

@media only screen and (min-width: 767px) {
#header_main > .container {
display: none;
}
}

.html_header_top.html_bottom_nav_header .main_menu>div, .html_header_top.html_bottom_nav_header .main_menu ul:first-child, .html_header_top .av_bottom_nav_header .main_menu ul:first-child > li a {
height: 140px;
line-height: 200px;
}