Hi Lakshman,
Thanks for contacting Syncfusion Support.
The behavior of EdgeLabelDrawingMode as Fit is, if the edge labels (first and last label) position of the axis exceed the chart area, then that labels half width size (maximum size of first or last label) is added as padding to the corresponding axis, in order to make the edge label fit into the chart area.
In zoom case, If the edge labels don’t exceed the chart area, then padding will not be applied to the axis, even though the EdgeLabelDrawingMode property as Fit.
Regards,
Devi