Thank you for using Syncfusion products.
We have checked the reported query “Swipe returns wrong index for the item when Grouping is enabled”. We let you know that the ItemIndex does not represent the index of the item in the ItemsSource collection, it represents the index of display items of SfListView. Hence you can achieve your requirement by using ItemData which you can get in SwipeEndedEventArgs instead of ItemIndex.
Please refer the following code example for the same,
private void ListView_SwipeEnded(object sender, SwipeEndedEventArgs e)
var data = e.ItemData as Register;
var registers = listView.ItemsSource as List<Register>;
_index = registers.FindIndex(itemData => itemData == data);
We hope this helps. Please let us know if you would require any further assistance.
Regards Gnana Priya N