How to solve error 524 for a kids account ?

My son has just downloaded battlefront 2 so I created a child's account for him which is connected  to my account. I understand that my son is to young to play online with this game but I have already made an age exemption for the game on his xbox so he should be able to play the game but it doesn't. Is there a setting that I need to change to allow him to play online?