Waterfall graphing issue

hello

i have managed to create a waterfall graph but getting an issue with one of the columns.

essentially i am trying to show the profitability from invoice sale to net profit....but where it states "ACCR" in the graph data, the graph is not showing up correctly to show the "waterfall" effect - see attached file.

can someone pls help? i have highlighted the row in yellow that is causing the issue...not sure what to do, stumped!

thanks in advance.