Often a transaction is being moved internally where a gain or loss is not actually realized.
If a transaction was sent internally between your personal wallets, you can set the gain value to $0.00. Save the value change and then add a comment to justify the new cost basis. In the other ledger, from your other wallet's transactions, you will want to carry over the cost basis. You can find the cost basis for a transaction by expanding the transaction details and looking at the total costs basis column for the inputs.
While reconciling your ledgers it is important to be consistent and reasonable in your adjustments. Comments and description notes are great details that will carry over in the Capital Gains Report worksheet NODE40 Balance generates with the IRS 8949 form.