Hi Robert ,
When you set the Auto RangeType to the PrimaryYAxis the chart will take care of the range and intervals. Please refer to the attached sample. In this sample when setting RangeType of PrimaryYAxis to Auto, and setting ForceZero to true, the chart will assign the minimum value to zero, maximum value to 200000 and interval to 50000.
http://websamples.syncfusion.com/samples/Chart.Windows/F75749_Aug12/main.htmCould you please check the sample and let me know whether you are able to reproduce the issue in this sample?. It would be helpful if you provide a sample or modify the attached sample to reproduce this issue. It will help us to resolve it as early as possible.
Thanks,
Nagaraj