After I upgraded to the latest version of slides, I noticed that a bargraph was still showing up with the stock values in the base powerpoint deck. It was replacing it in the code just fine, and when I went into Edit data in the slide, it showed the correct data and then the slide fixed itself.
I reverted back to 17.8 and the problem resolved itself, except that the pdf rendered still shows the old values. So now my pptx looks right but the pdf does not.
the values on the slide and corresponding labels are correct but the values and the labels on the pdf are incorrect. They were both output from the same reportdeck immediately after each other.