Drop a Button.
From the Properties, set the blendMode to SRC_OVER.
Click on the checkbox (on the right) : nothing happen : bug. Click again: the blendMode is set to nothing (null) : ok.
Try to set the id to null, by clicking the id editor checkbox. The checkbox is unselected, but the id is not set to null.
(Note this has also been reproduced on "GridPane constraints" editors checkbox)