Above the TreeView there is a Telerik.SegmentedControl, with two segments. If I click on one of the segments the ItemsSource of the TreeView gets updated by using .Add() or Remove() of the ObservableCollection.

If every Segment is called for the first time there is no problem. But if I want to clear all Items and display the empty treeView I get the following Exception.
Java.Lang.IndexOutOfBoundsException: 'Inconsistency detected. Invalid item position 0(offset:-1).state:14 md5a5af569a83c1a3f5c3a8a63bd7d39860.RadExtendedListView{c6376f1 VFED..... ........ 0,0-1200,840 #5}, adapter:com.telerik.widget.list.ListViewWrapperAdapter@b30041b, layout:android.support.v7.widget.LinearLayoutManager@3fd42d6, context:md5db22775bb305bf9756607f4261793d51.MainActivity@1d6cd4f