The Apple Screen Time is a feature available on all Apple devices that support iOS 12, iOS 13, iOS 14, and iOS 15. It is extremely popular amongst parents, and if used in conjunction with a content filtering service like CleanBrowsing can create conflicts.
The specific issue comes if you are using the Content Restrictions feature, specifically related to Web Content.
The issue presents itself because when this feature is enabled it intercepts requests, similar how most content filtering services work. Because this feature is on the device itself, it overrides what the network is telling the device to do.
Resolving the Screen Time Conflict
Resolve this conflict by setting the Web Content feature to unrestricted access. This disables the Screen Time filtering feature, and sets the filtering back to the network.