I’m guessing the answer to this will be yes but under family sharing your account now say adult and there is no longer a passcode used to lock your screen time settings correct? I’m guessing so. So all the above being true I would try the old turn off and on trick but in this case turn on then off. I would try turning web content to Limit Adult Websites performing a iPhone force restart, after restarting edit settings back to unrestricted and performing another iPhone force restart and checking if you have access to private browsing.