Not too long ago, we ran into an issue where none of the Fluid portal menu items were showing up in the menu. If I entered the URL in the browser for a Fluid component, it would show and work like normal. But, any content reference for a Fluid component wouldn’t show up. We could see them in Structure and Content, but not in the actual menu.
We finally figured out that the problem was a custom property on the Web Profile. The property is called “DisableFluid”. Navigation: PeopleTools > Web Profile > Web Profile Configuration
The fix is to just simply delete the custom property row. Don’t forget to restart the web server. Changes don’t take effect until you restart.