Button clicked event not triggering after lost focus event

I have a Winforms c# form with some comboBoxes , cancel and save buttons that work fine. I now need to capture when the user has finished entering text into a comboBox. I add an empty ( for now) lostFocus (or Leave) event to the combbox , which triggers fine. However if the cause of that event was a cancel or save button press , the corresponding event is no longer triggered. These buttons still work fine if pressed at other times.

Should these two event be firing in sequence or is there some better way to capture completed text entry?