Hi Bob,
My guess is that this is related to the long running issue with the burn charts in Scale, and how they work based on execution dates. I've pasted below some feedback that Josh42 got from SmartBear support, 3 years ago. Nothing has changed as far as I'm aware.
I have created a support ticket and raised my concerns about this issue being outstanding for so long, and suggest you do the same if the reports/charts are important to you.
As it turns out, the burndown and up charts as of now, use the date of the earliest execution as start date and the date of the latest execution of the final date and them on top of that it plots the chart it is plain wrong, so we are aware and we have addressed to get this fixed in the near future, also there are some known bugs in these charts, so eventually when you compare them they do not match correctly.
As soon as we get it fixed, we will get back to you.
Regards, Andy