Unreconcile Matched to Invoice

When you clicked on Matched to Invoice, you created Sales or Purchase Payments for the unpaid Sales or Purchase Invoices. These are what you unreconcile, not the Invoices themselves. So there is no process for Unreconciling Matched to Invoice.

If you are trying to unwind an incorrectly applied Payment, then follow the relevant Editing, Unposting and Deleting article.