The filtering mechanism is not triggered if the drop down of the control is opened and its ItemsSource is changed 

HighlightedIndex is lost when the drop down is opened and the ItemsSource is replaced.

Initially the events is triggered correctly and after switching between TabItems the event is not longer triggered. 

The issue also is reproducible inside RadDocking control.

The control is focused after the SelectionChanged event is triggered when selection is made with the mouse

As a developer I would like to be able to implement a custom highlighting logic of the items in the DropDown portion of the control so that I could implement a "best" matched item highlighting.

For example changing the highlighted index to be the first possible in SuggestAppend AutoCompleteMode.

As a developer I would like to be able to implement a custom highlighting logic of the items in the DropDown portion of the control so that I could implement a "best" matched item highlighting.

Add a possibility to set minimum populate delay to the control. It would be useful if a property like MinimumPopulateDelay is available to be set which would cause the populating of items to be delayed. Such feature would be helpful for cases when making requests to web server etc.

When custom items populating with delay is implemented the first item in the drop down is not highlighted

If the AutoCompleteBox is in SelectionMode="Single" editing the text of the SelectedItem will cause the textbox's CaretBrush to go to the end of the text.

Esc should be handled only when the popup is opened.

When an Item is selected, the SearchText property should be updated so it shows the item's text. At the moment it stays with the last entered text. The scenario is valid only for Single mode

When an Item is selected, the SearchText property should be updated so it shows the item's text. At the moment it stays with the last entered text. The scenario is valid only for Single mode

Make it possible to override the functionality of keystrokes in the control. A useful case is when placing the control inside RadGridView's CellEditTemplate and wanting to leave cell editing mode by pressing the escape keyboard key.

If the control is placed inside ScrollViewer when the mouse is over the AutoCompelteBox control the mouse wheel is handled leading to no scrolling of the ScrollViewer.

As a workaround the Foreground property of the AutoCompleteBox can be set to Black.