Thank you for reaching out about this and providing which wallets are using the API and CSV methods.
There are some API limitations with Binance that may be leaving out transactions that would cause inaccurate gains to reflect. Would you mind connecting with our support team so we can investigate what the transaction data discrepancies are within these two wallets?
For anyone encountering a similar issue, there are a number of reasons why your gains could be wrong. Missing transactions, incorrectly imported csv files are just some of them. We have a resource here on how to ensure your tax report is correct.
Thank you, David! Have an awesome day!