Go to
Settings and
addresses tab in your wallet to check if that address really belongs to your blockchain.info account. If it is, The problem is on blockchain.info's side.
You can contact their support regarding that and follow it up in social media accounts. Here are the links:
But if you want to access your funds quickly, I suggest to import in in
electrum as blockchain.info's support is a close relative of turtles.
*Please Note that, this requires you to have your recovery phrase. If you don't have it you can get it at Settings --> Security --> Wallet Recovery Phrase)
In electrum:
Standard Wallet --> I already have a seed --> Enter your recovery phrase --> Options --> tick the BIP39 Seed Box --> Leave the derivation unchanged --> Set a stong password
*Imported Addresses are not included in your recovery phrase/seed