To check just so the info is here for when BNGHelp will see it, are you are signed into Bungie.net as the Steam account while trying to create the clan? The account age check is for the Bungie profile but yours is 6 years old. Now you've linked the Xbox account, what it may be doing is cycling through accounts checking the Tower status of them to see if they've reached it and as the Xbox account hasn't (and cross-save isn't enabled) its throwing the requirements error. If you don't plan on enabling cross-save, then you may want to reach the tower on the Xbox account to see if that allows you past the requirements. As a side thing, you'll likely want to consider enabling cross-save regardless, with how the /join and /invite commands work, there's a good chance they will no longer function for people trying to invite and join your Steam account due to the Xbox account being higher in the order for look ups.