I’ve reproduced the problem with additional lines in the chart and added a ticket with ID SLIDESNET-42999 in our issue tracking system. Our development team will investigate this case. You will be notified when the issue is resolved.
The issues you have found earlier (filed as SLIDESNET-42999) have been fixed in Aspose.Slides for .NET 22.6 (ZIP, MSI).
You can check all fixes on the Release Notes page.
You can also find the latest version of our library on the Product Download page.