One of my categories isn't showing properly

Probably not the case, but just to be sure check the module assignment for modules in left module position. Maybe they are not set to show for that menu item...???

That didn't work. I did find out something new though.

I have that category in the home menu right. and the link there is linked to this category. Once I unlink it the problem goes away. I do need the link in the front though. How can I fix this?

When you enter configuration of that menu item there is (first you will see) option to change menu item type. Probably your problem comes from there because you selected to display that in wrong layout. If that is not the case you can always select type to be simple link.