Hi LINKConstruction,
Thank you for getting back to us on this and sorry to hear about your experience.
I just did a few tests in my test file by changing the name of the customer on existing invoices to the project then save and it worked for me. The existing invoices were moved to the new project I created.
I would suggest contacting our support team so we can assist you over a SmartLook (Screensharing) session. Here is a link to our Contact Us page:
https://help.quickbooks.intuit.com/en_AU/contact
Thank you and please let us know if you require any additional assistance.
