entry for sale not appearing on transaction report

Hello, I have been running monthly reports. (unified transaction report from Payments Reports Repository page). All is fine except so far; i've run reports from january through september, so far, and everything matches with my records. However, I did sell an item on September 11 which is not showing on the report. It was a straight-forward sale to a school in NY. It wasn't returned or refunded in any way. However, it is in my records as sold; i checked the order number to ensure it was not returned, and it isn't showing up on my transaction report. Not a big deal; every other report I've generated so far matches my data exactly. I just don't understand why this one entry is missing. The only thing that's different, is that it was sold to an employee at a school but I do not think that's a factor. any ideas? thanks!