I often struggle to find what actually toggles settings. It’s very common to have settings grey’d out when they actually affect things. In this case the “show fills” for section styles. If you’re having similar issues never assume that a grey’d-out setting won’t actually affect something - and try enables the toggle → basically you un-check “Use section styles”, check “Show filles” and then re-enable section styles.
AutoCAD even has one or two of these but only one or two. I don’t know why C++ based dialogs were so sturdy back then but they just were.