I am not sure why but the Disable Element “Content Title” is greyed out on posts and pages and I cannot enable it. I have checked the customizer, theme settings, beaver builder, and I cannot enable it.
This happens when the content title is already disabled. And it gets disabled when you use a page builder to modify templates or make content or if it’s already disabled by a Layout Element.
I’d check Appearance > Elements if there’s a Layout Element that’s already removing it.