After 1 million the decimal places of the labels are not correct, In your image. the labels on the horizontal axis go 999,992.50 - 999,995.00 - 999,997.5 - 1,000,000.00 - *1,000,003.00(should be 1,000,002.50) - 1,000,005.00 - *1,000,008.00(should be 1,000,007.5)
I have also updated your Telerik points.
Currently, the possible solution that I can suggest is to control what text is displayed in the axis by using a custom format provider: https://docs.telerik.com/devtools/winforms/controls/chartview/customization/custom-labels-text
Regards,