Remembering Pass words two different Credit cards same Servicing network

I have two Credit Cards one issued by a Retailer and one issued by an Oil Company both use Citibank to service their accounts. When I Iog into the Retialer's account apple Keychain drops the pass word for the Oil Company and denies access to the Retailer's account. So if I change the password on the Retailer's account. Then when I try to log into the Oil Company site it then drops in the pass word I just added for the Retailer.

What I am guessing that Apple Keychain sees only the start of the web address for both sites (Citibankonline account). and that's all.

Any way to get Key Chain to remember both passwords?

I tried the best I could with my explanation