Most likely, the age is set as below 13. If you put the wrong age by mistake and would like to change it, you can do it by reinstalling the game and setting the age again. Please note, however, that your locally-saved progress will be deleted. There is no option to change the age on an already existing account.
In case you’re above the age of 13 and you still cannot connect with Online Save due to other issues, feel free to contact our Player Support team.