Apex cross progression switch to xbox

Right Lukester192010​, that would be because your Nintendo account is linked to a different EA account. 

If you have any other emails that may have been used in the past, you can try logging in to see if you might have an EA account with that email, then check the connections page to see if that's where your Nintendo account is linked.

If there's an email you no longer have access to or you otherwise can't recall what other account may have been used, you'd need to speak with our support team to see if they can help track that down. 

Just to be extra clear, even if you locate this other EA account, there is no way to combine or move that progress to your Xbox account.