Some links aren't working

I am the developer for If you navigate to the “Projects/Services” page and scroll down, you’ll see groups of projects such as “Institutional/Medical”, “Office”, etc. Sometimes when i click the link, for the different grouping, my animation activates to open the different groupings of projects and other times it doesn’t work as though the clicking of the grouping was not registered. Does anyone know how i can improve the performance here so that clicks work every time?