xbox insider says underage so it's not letting me in despite my account being 18+

I know that there will be a lot of underage users on Xbox Live who are under 18 and their account will be classed as over the age of 18 that won't say anything, but I'm an honest individual and I want to get this off my conscience. I'd like a rep from Xbox
Live to set this straight for me. I do accept any fault and if my account gets banned, it's my own fault.

When I load the insider hub on my windows 10 and Xbox 1 it says that I am not 18 and so it wont allow me to use it but I am over 18.

So you never had this LIVE account when you were underage? You made it after you turned 18?

If you get the error your account is underage the date of birth you entered when creating the account makes you under 18

If you have another over 18 account on the console, you may use that as a "Parent" account and then you can authorise a DOB change on the underage account.