The XamDataChart uses the PlotAreaMargin property to prevent point symbols and lines to collide with axes. Now this gives other draw offs as shown below with PlotAreaMargin set to 10.

Now the plots give some problems with the display of grids:
The ends extend the series axis major ticks range (red circles)
The beginning is missing (green arrow).

I would prefer that the series if not zoomed are drawn above the axis and grid as shown with another graph component example below.