If you have the following PieChart with donut series definition:
<telerikChart:RadPieChart HeightRequest="200"
WidthRequest="200">
<telerikChart:RadPieChart.Series>
<telerikChart:DonutSeries ShowLabels="True"
ValueBinding="Value"
ItemsSource="{Binding Data}" />
<telerikChart:DonutSeries ShowLabels="True"
RadiusFactor="0.45"
ValueBinding="Value"
ItemsSource="{Binding Data1}" />
</telerikChart:RadPieChart.Series>
</telerikChart:RadPieChart>
On android works as expected:
On iOS the series are overlapped and not visualized as expected. The radius factor is not respected
On UWP the second donut series in not visualized and the radius factor is not respected.