There are a hundred good reasons not to use blockchain.com, from the fact that they are an insecure web wallet, they have had serious security flaws such as reusing r values, their support is legendarily useless, they were incredibly slow to implement segwit, and we regularly see users who cannot recover their private keys or coins despite knowing their seed phrase.

I don't know, but there are plenty of posts on this forum and on Reddit of people in a similar situation to OP - addresses or coins disappearing from the blockchain.com wallet and irrecoverable despite having the seed phrase. I don't know if there is an issue with blockchain.com generating addresses from completely different seed phrases, or maybe they mess up and use arbitrary derivation paths that no one has been able to figure out yet, but either way, it happens not infrequently and they've done nothing to address the issue.