submenu doesn't appear correctly when menu tab is clicked, fine during rollover

I have a submenu within one of the main tabs of the navigation bar. the tab is called “works” with sub categories “recent” and “archive”. my portfolio is in those two albums. when you roll over “works” and down, everything looks great. however, when you click on the “works” tab itself then roll over, some lines disappear and others turn white instead of gray.

i’m also wondering if i can’t fix this issue if I can just disable clicking on “works”, “recent”, and “archive”, basically just have those as roll overs with only the actual series titles clickable, for example, “tiles”, “machines”.

thanks!

my url is https://www.lu-zhang.com/test1