I didn't know that blockchain had the possibility of using 2 passwords, I'm going to take the guess and say it's an old feature.
It is, and I'm not sure if thats an old feature:
https://support.blockchain.com/hc/en-us/articles/210929703-Advanced-Security-Unfortunately, there isn't anything OP can do. Even Blockchain's support can't help him (according to the link above).
Second Password
For additional security, you can choose a second password that is asked whenever you want to spend funds. As with your main password, if you forget your second password, we cannot reset it for you. Make sure you backed up your wallet before setting a second password. Create a second password by clicking Set Second Password.