Credit memo re-generated everytime.

Summary:

Credit memo is regenerated everytime Generate invoices process is run

Content (please ensure you mask any confidential information):

An invoice was cancelled by the user by mistake and it generated a projects credit memo on the contract invoices screen. The user has then deleted the credit memo using the 'Delete invoices' process and the credit memo was deleted.
However, the event is still set to pending adjustment instead of Fully invoiced, and the credit memo is regenerated whenever generate invoices process is run again.
We are unable to prevent this from happening.

Version (include the version you are using, if applicable):