This may be completely unrelated, but I know that until relatively recently (18.12 maybe?), the category page did not even have a page options component available. So, if it was in an included quilt (usually the header quilt) it would not have rendered anything.
When we were rolling out a feature that introduced some options at the category level, we noticed that a lot of sites had simply removed the component from their category page's header quilt in Studio, and they had to add it back in to access the feature (category subscriptions). Perhaps the site you're working on is in this state?