According to PSD2 regulations, banks are required to disclose only payment accounts. Whether non-payment accounts (such as savings, investment, and potentially credit cards) are included in the returned data depends on the bank's decision.
Unfortunately, if a bank decides to return only one account, there is little we can do to alter this outcome.
Your best course of action is to directly contact the bank and seek clarification on the specific types of accounts accessible through their Open Banking channel.