In your csv file, does it show these orders as having no processing time associated with them? There is a known glitch where some orders lose their processing time and this causes Etsy to mark them as late dispatch. It's been a reported issue since the inception of the programme, Etsy seems to have no interest in sorting it. I would bug Etsy support and get them to escalate it - the more reports they gets the more incentive they have to prioritise a fix.
I've noticed recently as well that when comparing an newer version of the csv to an older version, some of the orders that were originally recorded as all fine have been updated to show a missing processing time and thus dispatched late. I originally see all 'yes' and dispatched on time, and then when I download again a few weeks later some of those same orders are now 'no' processing time and marked as late.
Someone reported years ago that Etsy support had told them it was an issue caused by a customer checking out from multiple shops at the same time. I've never received confirmation from Etsy on that but it does seem so without rhyme or reason as to which orders are hit that an explanation like that would make some sense.
