Parabola Primary Menu Broken

My Primary Menu is Parabola is somehow broken. I was trying to add a page to the primary menu navigation. Now somehow three of my major navigation buttons are gone and anytime I try to add them back, the menu I’m working in get’s unchecked as the primary nav and I lose any pages I tried to add. I’m not sure what to do to fix this. Any help would be so appreciated. My website is bgcbigs.ca and I’m missing the Careers, Contact Us, and Donate parts of my menu.