@rcgillis Upon further investigation, it doesn’t look like Quick Submit vs. NativeXML import makes a difference in this case. Another much smaller journal that was added at around the same time is also showing the calculation problem, and those 40 back articles were Quick Submitted. See screenshot below for details.
I checked more of our other journals, including ones that started on OJS and didn’t have any back content, and there is something wrong with the calculations on each.
Sorry to be the bearer of bad news!