Qt Designer's Tab Order List window broken - cannot drag/drop

"Tab Order List" window is broken in Qt Designer - cannot drag & drop widgets in the list.

To reproduce:
1. Open Qt Designer

2. Create a new widget.

3. Drop 3 push buttons on it.

4. Enter "Tab Order" mode by clicking "Edit Tab Order" button.

5. Right-click on the widget, click "Tab Order List..."

6. Try to drag one of the widgets in the list up or down.

Result: Dragging is stuck, everything is unresponsive until Esc is pressed.

This used to work in Qt4.

I'm attaching an example ui file with 3 buttons.