Hello. You already have cross save activated. You would not have never been able to cross save if you did not know the credentials to the old Steam account. If it is saying the username does not exist, you will need to contact Steam Support for further assistance. Also to keep in mind, you cannot unlink accounts while cross save is active.
English
-
Can't Bungie just unlink the account for me? Its on their website they can do it I'm sure.
-
Unfortunately no. Due to security reasons they cannot unlink your accounts. That is something you need to do yourself.
-
I have proven this is my account by logging in. They could also just send an email it doesn't need to be so difficult.
-
Please contact Steam Support for further assistance to gain access to your account.