Sub menu items could not be clicked until its parent is active

I changed the sub menu to be horizontal in Adamos. The sub menu could not be clicked until parent is active. This is the code I used to display and hide the sub menu. Is something wrong?

.main-navigation .current_page_item ul.sub-menu , .main-navigation .current_page_parent ul.sub-menu {
display: block;
color:#adadaf;
background-color:#fff;

}

.main-navigation li:hover ul.sub-menu {
display: block;
color:#adadaf;
background-color:#fff;

}

.main-navigation .current_page_item ul.sub-menu:hover, .main-navigation .current_page_parent ul.sub-menu:hover {
display: block;
color:#000;
background-color:#fff;
}

.main-navigation:hover li.current-menu-item .sub-menu, .main-navigation:hover li.current-menu-parent .sub-menu{
visibility: hidden !important;
display: none !important;
}

.main-navigation li.current-menu-item:hover .sub-menu, .main-navigation li.current-menu-parent:hover .sub-menu{
visibility: visible !important;
display: block !important;
}

.main-navigation li ul li.current-menu-item:active .sub-menu, .main-navigation li ul li.current-menu-parent:active .sub-menu{
visibility: visible !important;
display: block !important;
}

Thanks in advance.