Hi Tony,
In your ul#cssmw16 ul.level-1 rule [ CSSMenuWriter/cssmw16/menu.css (line 96) ] you need to reduce the 'left' property by (just) 1px:
ul#cssmw16 ul.level-1 {
left: 180px; /* changed from 181px */
}
It seems to be that 1px gap that is allowing the Level-1 menus to disappear.