Has anyone else had problems with Royal Mail first scan of package being late?

I have been on the SFP trial for 2 months, and have fulfilled 106 orders and they HAVE ALL BEEN HANDED TO ROYAL MAIL ON-TIME - however my on-time shipment rate is currently 97.2% as 3 packages did not receive their first scan until the next day?!!

The weird thing is that all packages with late scans were handed to Royal Mail in sacks with other packages that did get scanned in time - so its not like the whole sack has delayed. This has happened on 3 separate occasions.

I really dont know what to do, I am starting to think that completing the trial with Royal Mail is not going to be possible. Is there anyway to guarantee a package gets scanned on the day its handed to Royal Mail??

Thanks