Xbox content restriction?

So my problem is that I turned on the Xbox as usual, and opened my game (which is from 18) and it didn't work. It says that I need my parents' permission and that my content restrictions are classified. I don't think my mother changed anything because she doesn't mind anyway and I can't change it somehow in the settings: /

In the settings everything is set from 16 but there's no way to change that. Really need help: /

That needs to be changed with the Microsoft account that is considered your legal guardian (probably your mother)