Place a RadComboBox control in a RadPane. Make it floating and dock it again. When selection is changed, the SelectionChanged event is fired multiple times.

When filtering is enabled, enter text that doesn't exist in the items and when the focus is removed the text entered is deleted, but it should stay.
The solution of this issue was implemented by a new feature in the control which determines if the Text of the RadComboBox should be updated on LostFocus or not.
Simply set the UpdateTextOnLostFocus dependency property of the control to "False". By default its value is True and no change in behavior should be observed.
The UpdateTextOnLostFocus dependency property is available in the 2015 Q2 SP1 release.

When the ComboBox is non editable.

When the CheckBox is focused the issue is appearing.

Available in LIB version 2016.2.905, it will be also available in the 2016 R3 Release.

When IsEditable is set to true the SelectedItem is not updated if you delete the SelectedItem's text to match another existing item.

According to the following article, when the UpdateSelectionOnLostFocus property is set to True and you enter a text that cannot update the selection, once the control loses the focus, the typed text should stay in the textbox. 
https://docs.telerik.com/devtools/wpf/controls/radcombobox/howto/perform-selection-only-lost-focus

However, this doesn't happen if an item is already selected. In this case, the searched text is cleared. If you do not have a selection, then the text stays on lost focus. 

To work this around, you can cache the value of the RadComboBox's Text property in the PreviewLostKeyboardFocus event handler and then restore it in the LostFocus event handler. 

private string textCache;
private void RadComboBox_PreviewLostKeyboardFocus(object sender, System.Windows.Input.KeyboardFocusChangedEventArgs e)
{
	this.textCache = this.comboBox.Text;
}
private void RadComboBox_LostFocus(object sender, RoutedEventArgs e)
{
	this.comboBox.Text = this.textCache;
}

IsEditable=True and ReadOnly=True

RadComboBox with IsEditable = true, IsReadOnly = true and IsFilteringEnabled = true. Select an item and then in order for the filtering to work you have to delete the selected text with Backspace

After RadComboBoxs DropDown (PopUp) is open moving the focus with Shift+Tab skips the Combo, Tab does not skip it


Available in R2 2015 Release (v.2015.2.623.40)

The same issue can be observe when placing the control inside ToolBar.

Steps to Create Problem using  EditableTextBoxTemplate_WPF sample project provided by Telerik:(modified project is zipped and attached just in case)

- Edit Example.xaml to add "AllowMultipleSelection="True":

1) Run project 

2) Click drop down button to see list in the drop down

3) Type "Global" (at this point it should autocomplete "Global Corporation")

4) Without clicking on anything or Press space bar to continue typing (type space character)

5) Typed text will disappear leaving only space character behind - At this point, nothing is selected.

This does NOT happen if typed text before space does NOT match with any item from the list. 

This does NOT happen if AllowMultipleSelection set to false. 

This does NOT happen if dropdown is NOT open while typing.

Available in LIB Version 2016.3.1010, it will be also available in the 2016 R3 SP1.

When you start navigating through the ribbon via the keytips or the arrow keys, and you get to a RadRibbonComboBox, this opens its drop down which contains RadRibbonComboBoxItems. 

In this case the keyboard navigation (using the arrows) of the RadRibbonComboBox doesn't work. This happens because the ribbon navigation implementation interfere with the combobox navigation.

When you click on the TextBox of an editable RadComboBox all the text should be selected, but it is not, even when SelectAllTextEvent="All" is set. The text is blinking as selected for half a second and then deselects.