If you want to see the invoice that you feel is odd or different from the usual transaction that you do, you can look at the history to track what data has been changed, so that you will know who changed it or what was changed in that invoice.
I. View Update History for Specific Invoice Number
Step 1. To Check it you can go to Order - Click at one invoice - then select Invoice update on More Menu

Step 2. Try you change the total payment of the invoice, date and invoice number

Step 3. Check at the Update History for the invoice, it will be shown like this when you open the history

II. View Update History for All Invoice
Step 1. Go to Orders -> More Menu -> Invoice Update History


You might also like to read these articles below:
To configuration customer invoices, you can check this article Customer Invoice Printing Configuration
If you want to make write off customer invoices, you can check this article Write off Customer Invoices