If the public address is different, it is not the same seed phrase. The only way that the same seed phrase can generate different account addresses is if the seed phrase was generated by a different wallet that used a different derivation path.
Did you bring the seed phrase from another wallet by any chance?
When did you first create this wallet?
When viewing on Etherscan, does the account have historical activity?
Were you using a hardware wallet previously, and the funds were on that hardware wallet?