Twitter cannot be blocked on childs iPhone
Twitter seems to be the only site that cannot be blocked on an iPhone. Even when you specifically add it to content restrictions.
iPhone XR
User profile for user:
Missy5937
User level:
Community Specialist
Hello Seeyafoo,
Thanks for posting in the Apple Support Communities. We're happy to look into this with you.
To clarify, are you attempting to access Twitter via Safari or are you using the Twitter app? If you're blocking the website but still able to view content in the Twitter app, you'll want to adjust Content and Privacy Restrictions for App Store. You can read more about this option in Use parental controls on your child's iPhone, iPad, and iPod touch - Apple Support.
If the scenario above is not exactly the issue you're facing, then contacting Apple Support to report the inability to block Twitter is the best option, so they can investigate why this is happening. You can reach them directly at Get Support.
Best regards.