Writing History > Export exports Words (Draft Total) as 0

I might be doing this wrong, but Scrivener’s export for writing history isn’t working as I expect.

I used Project > Writing History > Export to export the writing history.
I checked “Words (Draft)” and “Words (Draft Total)”.

What I expect to see in the CSV:
[Date],[Words(Draft)],[Words(Draft Total)]
where “Draft Total” represents the total words in the manuscript draft at the end of the day, like you would see by using Project > Statistics > Compiled > Words.
I would expect this number to change daily by the amount in "Words (Draft), starting from about 47K.

What I actually see:

... and so on ...

Date and Words(Draft) are correct, but the “Draft Total” is usually 0. It’s also missing the header.

Any thoughts? Is there a different way I should try to get a history of total words in the manuscript draft at the end of the day? I’m open to anything including external programmatic solutions.

Edited to add: I sync this project via DropBox between two Macs and an iPad, in case that matters.

The Words (Draft Total) in the export isn’t one of the columns displayed in the writing history. The total column there is the net total for the day adding up draft and other. You are right that it does not seem to export correctly. In one of my own projects the total does go up cumulatively but with days with 0 in between. In another project it doesn’t go up cumulatively. And as you say the column doesn’t get a header. I’ll pass this up to the dev team for their comments as it could be a bug.

Thanks Rob! That agrees with my expection. Looking forward to it because this is one of the features I relied on in choosing to switch to Scrivener recently.