title: Highcharts shared tooltip formatter doesn't get passed all points
body: <p>I have a chart which displays 3 series of data initially.</p>
  
  <p>A shared tooltip formatter is used for the initial 3 series and this works correctly.</p>
  
  <p>However after adding 2 additional series to the chart, it seems that when the formatter function is called it gets passed points on either the original 3 series or the 2 new ones.</p>
  
  <p>The result of this is that I see one tooltip for the 2 new series when mousing over a point belonging to one of them, and I see the shared tooltip for the 3 original series when mousing over a point belonging to one of those.</p>
  
  <p>What I want is for the formatter to be passed points for all series and to just have one tooltip for all points.</p>
  
  <p>The formatter code looks like this:</p>
  
  <pre><code>tooltip: {
      formatter: function() {
          var s = [],
              addedDateLabel = false;
  
          console.log("In tooltip formatter", this);
  
          $.each(this.points, function(i, point) {
              var date = new Date(point.x),
                  month = config.monthNames[date.getMonth()],
                  year = date.getFullYear();
  
              if (addedDateLabel === false){
                  s.push('&lt;span&gt;&lt;strong&gt;' + month + ' ' + year + '&lt;/strong&gt;&lt;/span&gt;&lt;br&gt;&lt;br&gt;');
                  addedDateLabel = true;
              }
  
              s.push('&lt;span style="color:' + point.series.color + ';font-weight:bold;"&gt;'+ point.series.name +' : \u00a3'+
                  CurrencyFormatting.formatValue(point.y.toFixed(2)) +'&lt;span&gt;&lt;br&gt;');
          });
  
          return s.join('');
      },
      shared: true
  }
  </code></pre>
  
  <p>The console log in the above shows the following in the console:</p>
  
  <p><a href="https://i.stack.imgur.com/yMmot.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/yMmot.png" alt="Console output"></a></p>
  
  <p>Where you can clearly see that sometimes there are 2 points and sometimes 3.</p>
  
  <p>I have tried calling <code>redraw()</code> on the chart after adding all the series but that doesn't seem to help.</p>
  
  <p>I'm aware that I could probably just destroy the chart and create it again from scratch but would like to avoid that if possible.</p>