Hello,
Thanks for describing your unique situation and reaching out for support.
I want to point you in the right direction for support and advice. Since altering previous transactions from a closed fiscal year will impact your books, I highly recommend consulting with your accountant before moving forward. They'll be able to guide you on the best practices for dealing with this situation.
I also recommend that you then reach out to our Desktop phone support team for clarification on how to make the proper changes (if any) in QuickBooks. The number to call is 877-772-9158. Agents are available 24/7, so you can call whenever it's convenient for you.
Let me know if you have any other questions.
Have a great day!