It’s working fine for me. It could just be your browser, as I’m using Chrome and it’s working perfectly….I also did a quick test on Safari, and Opera. Sometimes different browsers work and display sites and their functionality different than others….since their software is different.
If your browser is still not displaying it correctly, you can adjust the code around line 2064 in your css to look like this –
.genesis-nav-menu .sub-menu .sub-menu {
margin: -45px 0 0 200px;
}
The code in your css at the moment is set at 201px, so change that to 200px so it will move that section over a pixel and then there won’t be a gap in between.