Displays NaN in secondary y axis of Timeseries graph

Hi,

I am using the timeseries graph to display the property history. I also have a checkbox to select/deselect a parameter that uses the secondary y-axis. On deselecting that parameter I get NaN values on the secondary y-axis. I disabled the secondary y axis autoscale and then it wasn't giving NaN on the axis. But I can't disable it as it's min and max range is not known. Is there any other way so that on deselecting the parameter, I wont get NaN values on secondary axis?