Hi Dev clinicea,
Greetings from Syncfusion.
We have validated the provided screenshot and we suspect that you have set the numerical axis Maximum and Minimum property value in your sample. We would like to let you know that when using the axis Maximum and Minimum, Additional RangePadding will not consider.
Please ensure whether you were using the Maximum and Minimum property in your sample or not. You can also set the RangePadding Additional for the DateTimeAxis(PrimaryAxis based on the screenshot).
We would like to suggest you to use the default DataMarker LabelPosition Auto which will be place the datamarker based on the available space without cutting as per your requirement.
series.DataMarker.LabelStyle.LabelPosition = DataMarkerLabelPosition.Auto;
<chart:DataMarkerLabelStyle LabelPosition="Auto" TextColor="White"/>
If the above solution does not resolve your issue, please provide the chart related code snippet and the datapoints details which will be helpful for us to investigate the issue and provide a solution at earliest?
Please let us know if you need any further assistance on this.