Chart legend does not not release old fields when updating fields

I have a bar chart that I load with dynamic amount of y-fields. But the legend will not release these old fields when I´m updating with .setTitle(titleArray) and setYField(fieldArray). They are empty but it does´nt look nice. Before that I´m updating the store.

Chart-legend-will-not-release-old-names.png

Is there any other way to update a chart with less or more fields?

I´m using a model that sets the limit to 8 fields.

Before I´m loading data to the store I need to call removeAll()-method or else old bar remains in the chart.

Chart legend does not not release old fields when updating fields