Put several Pie charts in a StackPanel and set the WidthRequest and HeightRequest to let's say 60. You will notice that the circular pie itlsef appears much smaller than the expected 60. In Android and Windows Phone it appears as expected.
Add the ability to render points outside of the plot area when the data point value exceeds the explicitly set Min or Max values of the horizontal axis. On Android and iOS, the line series will continue to extend off the plot area to a point that isn't rendered. Here's a screenshot, notice the line coming in from the left side of the plot area: https://www.telerik.com/clientsfiles/77e02115-6de0-4dd0-b572-5d5bc17a59b9_xamarin.jpg On UWP, the beginning of the line series only starts on the first plot-able point. Here's a screenshot, notice the start of the line series: https://www.telerik.com/clientsfiles/d8c342e3-608b-40eb-95eb-8bd5e0dbc2e6_uwp.jpg
If you have a Chart with BarSeries and TooltipBehavior defined, the tooltip of each bar is shown only when the user taps in the area around the tip of the bar.
The expected behavior is the tooltip to be displayed when clicking anywhere on the bar.
If we have a Chart with combined barseries and lineseries, and the lineseries is added first, the bars are misaligned - they are not placed in the center of the axis label on Android.
As a workaround, make sure to add first the barseries, then the lineseries.
As of the latest release (10/04/2019) RadPieChart with a PieSeries having LabelBinding set to a property name, and ShowLabels set to True, with the list of data bound to ItemsSource containing one or more empty pie slices (a null in the list), causes a System.Reflection.TargetException to be thrown on load of the page containing the chart in iOS (this scenario works fine in UWP).
I am using the latest available Visual Studio 2019 (16.3.5) and the latest available Xamarin.Forms package (4.2.0.848062) and testing on an iPad with iOS 13.1. The reason I need to have a null value in the list is so that the custom color palette I'm applying will always apply the same colors to the same data points (pie slices), even though in some cases, zero or one or two of the three pie slices will have no data value (and so should not appear in the chart, but still "use up" the corresponding color in the 3 colors of the palette).
In the 08/02/2019 release, this scenario worked fine in iOS (the 09/13/2019 release had the https://feedback.telerik.com/xamarin/1431067-chart-ios-invalidcastexception-is-thrown-when-the-chart-is-loaded issue, which is now resolved in the 10/04/2019 release, but which prevented my testing in iOS since in my app I had RadCartesianCharts on the same pages as the RadPieCharts).
The newly broken functionality in iOS could possibly be related to two other items that are marked completed:
https://feedback.telerik.com/xamarin/1366403-piechart-tooltip-behavior-is-not-working-properly (in 10/04/2019 release)
https://feedback.telerik.com/xamarin/1365842-chart-null-value-support (in R3 2018 SP release)
If the series is added after the page constructor, the vertical axis labels are not shown. As a workaround, create the series in the constructor and set its ItemsSource at a later stage.
If you have BarSeries with CombineMode set to "Stack" with zero values, the bars are placed to the maximum of the y-axis. As a work-around, you would need to manually adjust the Maximum value of the vertical axis.