Screen time missing ‘Private’ window

I have screen time parental controls set up on my teenager’s phone so that they can limit their use on certain apps, however we recently discovered that the ‘Private’ tab is not accessible to them, and they can’t delete their search history. I have tried changing their screen time content restrictions to unlimited and that didn’t change anything. I cannot find any settings that would block this setting. Any suggestions?

Their phone is on iOS 17.1.1, and the model is an iPhone Xs