Indeed when you have chosen Bar Series and more than 1 serie belong to one and the same XAxis Label, the Chart "Clusters" the bars. I'm not sure what you mean by saying that you want to "uncluster" them. I'm assuming that you'd like to see the bars stacked.
To have stacked bars you may follow our help topic and demo. The topic demonstrates how you can bind a single series to a List of objects. However to have stacked bars with N bars in a stack , you will need N number of series. The approach is absolutely the same as the one you'll use to cluster the bars. The onliest change needed is to set the Type of the series to StackedBar and Voilà.
P.S. If this is not what you expect as result from the chart, please send us a sample image which shows how you'd like the bars to appear and we'll get back to you with our suggestions.
All the best,
the Telerik team
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