Basically blockchain.info used to have a second password feature, they deleted this. Does anyone else know a web wallet with a second password? does the trezor / ledger have a second password?
Blockchain.info is now blockchain.com. You sure they deleted the second password feature? Why would they remove a very important security feature? You should check again. Probably someone turned it off from your account and your account has been compromised.
Even if a web wallet has a second password, they are not secure at all! Never store your coins in a web wallet. There is a high chance you will lsoe everything. As for trezor/ledger, they aren't web wallets. They are hardware wallets and quite secure.