In the SearchViewSingleLineItems Telerik template, it places a RadListView in an auto-sized RowDefinition. As a result, this causes the RadListView not to appear on iOS. This should be a star-sized row as mentioned in this UI for Xamarin documentation.
Although unrelated to the issue, the deprecated RadAutoComplete is being used for the example. Please update it to use the new RadAutoCompleteView instead.
Please update this template (and any other search templates that might have the same issues), thank you.