How to stop new series from being automatically added to a chart?

When you add a new series to a document, it’s automatically included in your charts. To disable this, you have to do the following for each of the charts:  

  1. Click on an empty area in your chart (i.e., below the x-axis). This opens the general chart properties under the Presentation properties tab.
  2. Click 'More' in the chart elements box.
  3. Now, untick the option 'Include new series automatically'. 

See here pre-1.26 version view