Hello Connor Wease,
Welcome to Microsoft Q&A forum.
Usually, changing your account age will not automatically let you access age restricted content, that is to prevent real children abuse this to access contents that is not meant for them. In this case, there might be some leftovers restriction that was cache by your account, can you please try to create an adult account, add your account on it as a child account to see if you can remove the restriction?
I'm waiting for your reply.