If it was a recent sale, it likely simply hasn’t indexed yet and will show as a sale shortly. If it was a purchase you made yourself, it may have been recorded as a personal transaction rather than a sale.
Can you look for those prior sales in your earnings report in the prior years when the invitations sold? Perhaps you could take those earnings results and report those to Zazzle so they could correct the sales stats for those items. If they went pink (cancelled), then they would not show in the sales stats as being sold.
Another thing to consider - there are printed stats and digital stats for invitations. If your invitation sold as a digital download, you can find those sales stats under the digital stats for that product.
