Labels (instances of the LightTextBlock control) remain on the render surface after the ItemsSource is replaced dynamically and the row or column count is changed. As a workaround, the control can be redrawn manually to clear the surface:

If you update the property value bound to the Value of the cells at runtime, this change doesn't reflect in the UI. To reproduce this you will need to assign a colorizer to the CategoricalDefinintion and set the colorize's IsAbsolute property to True.

To work this around, reset the Definition property of RadHeatMap after the values change.

As a workaround, you can set these properties in the Loaded event of the control in that scenario.

The labels are not positioned correctly when some of the cells are empty.

Available in LIB version: 2016.1.314