Apple Books Store still enabled. Restrictions say it's disabled.

I like to restrict access to my iPhone SE's ability to browse/purchase books off the Book Store, especially books rated Explicit. I recently downloaded a free Apple Book and Audiobook last week, and now the Books app is permanently able to access the Book Store and books rated explicit. I had my Mom punch in the screen time passcode, and I switched the Book Store off and back on, and did the same with explicit books. No change.

I really, really do NOT want to have the Book Store on all the time, much less explicit books available for me to download. Since the restrictions say they're disabled (and obviously they're still enabled), this is an issue I'm sure parents will want looked into immediately.

Is this an issue that only an iOS update can fix?