I have created a sample project with two ListView controls The second is added inside the first ListView ItemTemplate. In the project, there are two different DataSources and two collections. Download the provided example, use it as a base and extend it further per your exact scenario.
ScrollView objects should not be nested. In addition, ScrollView objects should not be nested with other controls that provide scrolling, such as CollectionView, ListView, and WebView.
The same is valid for Telerik .NET MAUI controls that have internal scrolling, controls like: DataGrid, ListView, DataForm, ItemsControl.
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