OxyPlot Odd Marker Placement With LineSeries -

i coding basic cumulative moving average lineseries markertype = markertype.circle. reason marker ending not on line. pan , zoom disabled on y axis. have included picture of it. know of reason why doing this?

this how i'm adding series plot

   <grid x:name="gridchart" column="2">     <grid.rowdefinitions>         <rowdefinition height="auto"/>         <rowdefinition height="*"/>     </grid.rowdefinitions>     <textblock grid.row="0" background="yellow" padding="4" fontweight="normal" fontsize="12" visibility="collapsed"/>     <oxy:plot grid.row="1" x:name="plotstriketheobasis" mousedoubleclick="plotstriketheobasisonmousedoubleclick" margin="5" legendplacement="inside" mousewheel="plotstriketheobasisonmousewheel">         <oxy:plot.annotations>             <oxy:lineannotation type="horizontal" y="0"/>         </oxy:plot.annotations>         <oxy:plot.axes>             <oxy:linearaxis position="left" x:name="axisqty" title="qty" iszoomenabled="false" ispanenabled="false" minorticksize="0"/>             <oxy:linearaxis position="bottom" x:name="axixbasispoints" title="basis points" minorticksize="0" maximum="{binding max, mode=twoway}" minimum="{binding min, mode=twoway}" absolutemaximum="200" absoluteminimum="-200"/>         </oxy:plot.axes>         <oxy:lineseries x:name="lineseriesmovingaverage" visibility="{binding movingaverageqtychecked, converter={staticresource booleanvisibilityconverter}}" itemssource="{binding movingaveragedataseriesset}" datafieldx="basispoints" datafieldy="quantity" title="cma" markertype="cross" markerstroke="hotpink"/>     </oxy:plot> </grid>  public partial class theobasisstrikechartwindow : window {     private static readonly ilog log = logmanager.create();      private theobasishistogramviewmodel _viewmodel;      internal theobasishistogramviewmodel theobasishistogramviewmodel     {         { return _viewmodel; }         set         {             _viewmodel = value;             gridchart.datacontext = value;         }     }              public theobasisstrikechartwindow()     {         initializecomponent();          theobasishistogramviewmodel = new theobasishistogramviewmodel();     }      private void refresh()     {         try         {             _viewmodel.refresh();         }         catch (exception ex)         {             log.error(ex);             messagewindow.show(                 "error occurred loading window. please report staff",                 "error", messagewindowimage.error,                 messagewindowstartuplocation.createcenteredon(this, this), messagewindowbutton.ok);         }     } }   public class basispointsqty {     public double basispoints { get; set; }     public double quantity { get; set; }     public basispointsqty(double basispoints, int quantity)     {                      basispoints = basispoints;         quantity = quantity;     } }  public class theobasishistogramviewmodel : propertychangednotifier {     public observablecollectionex<basispointsqty> movingaveragedataseriesset { get;}      public theobasishistogramviewmodel()     {         movingaveragedataseriesset = new observablecollectionex<basispointsqty>();     }      public void refresh()      {         // update movingaveragedataseriesset here     } }