sorry it won't let me message you. how can you help
Be very careful with "newbie" accounts that PM your (or request PMs or Telegram etc) offering to "help"... especially if they start asking for username/passwords/wallet-ids/seeds/private keys etc... There are a lot of scammers on these boards and scams are not moderated here.
'Tis indeed a bit of a puzzler as to why the balance of this address is not showing up as available in your wallet. It seems that the blockchain.com system believes that this address
was part of your wallet at some point... but now it would appear that it doesn't currently have access to the private key, so isn't showing the available balance (it's treating that address as "watch only").
Honestly, at this point, you really need to get some sort of solid answer from blockchain.com support as to why this is displaying like that. I suspect that it might be related to the "upgrade" where they moved everyone to HD wallets. Unfortunately, I've only ever heard bad things about blockchain.info/com support
Were you able to get your wallet.aes.json file retrieved with btcrecover?