Hi Hanspeter Bossard,
Thank you for your purchase.

It is not possible out of the box but it can be accomplished with little custom coding. You can use wpDataChart  callback to create different chart types for different series. You can take a look usage and examples how to use wpDataChart callback on this link. If you need our assistance we can offer you our paid customization service.

Hi Hanspeter Bossard,

This is an example for Highcharts, but you have to modify it by your needs. In this example first serie is set to column chart type and second one to spline chart type.

<script type="text/javascript">
jQuery(window).load(function(){
if( typeof wpDataChartsCallbacks == 'undefined' ){ wpDataChartsCallbacks = {}; }
wpDataChartsCallbacks[1] = function(obj){
  obj.options.series[0].type = 'column',
  obj.options.series[1].type = 'spline',
}
});
</script>

Hi Hanspeter Bossard,

You are welcome. We'd greatly appreciate it if you could take a minute and leave a review on CodeCanyon on this link. Thanks!