I understand how overwhelming it can be to fix duplicate income entries in your Profit and Loss report, especially since this issue spans an entire year of transactions. Let me help clarify why this happened and provide guidance to fix it, Rose.
Income duplication occurs when invoice payments are recorded, and transactions downloaded from your bank feed are added instead of matching them with existing payments.
To prevent duplicates, it's advisable to match the invoice payment with the downloaded transactions instead of using the Add function.
Given that this process requires a significant amount of time to correct manually, I recommend consulting your accountant. They can guide you in navigating the steps below to ensure the accuracy of your financial records.
To resolve this, let's review the workflow for each duplicate pair. Identify each one by drilling down into your Profit and Loss report income total. Please see the attached screenshot for visual reference.

For the invoices, change the associated payment's Deposit to account to Undeposited Funds, then locate the duplicate bank deposit and ensure it aligns with the payment from Undeposited Funds. Please delete any unnecessary Add funds entries.
For sales receipts, delete the duplicate Deposit transaction from your bank register, as it has already recorded the income.
Moving forward, always use the Match function in your bank feed. This process will help ensure the system accurately associates it with the correct transaction rather than creating new entries.
If you have further questions, add a comment below. We're always here to help.