Woocommerce Admin reporting – different numbers than old?

With the news that the old reporting is going away (or so I heard) we started to compare some numbers from the old reporting system to the new one. I started with our January numbers, and when running for the month there were discrepancies, so I started going day-by-day. January first through the third were the same in both, but on the fourth we ran into a case where the gross and net totals, and the number of sales were the same, but the number of items sold was different.

I ran some MySQL queries and was able to reproduce the numbers of the old report for items sold, but I can’t determine how the new numbers are arrived at. In this case, it was off by 11 or about 1.8% if that is relevant. When I clicked on the “Items Sold” box to drill down, the product list there had some parent items for which we only sell the variations. I don’t understand how that is possible, and in fact they do not exist in the order line items, all of those have the metadata for the variation as well as product ids, so it should only point to the variation not the parent product itself.

If there is a better way to report this or to help track down why there are discrepancies, I’d be happy to engage with someone on it.