BUG? Sunburst blank figure with negative values


I have an itemized retail store sales data in Pandas DataFrame with some negative values in ‘qty’ when there is a returned merchandize. The Sunburst plot in plotly.express shows a blank (as above) unless I drop the rows with negative ‘qty’.

Is this a bug? How can I work around this? I do want to included the return qty in the analysis. They should be substracted from total in branchvalue calculation.

Thanks for any help!