Wrong (unwanted) derived attribute insertion addition in membership modal page

1) Log into console as admin and create or edit user
2) in user modal page go under roles tab and add some membership that has a normal or virtual attribute in its template; for example use role "child".
3) in membership modal page go under normal or virtual attributes tab and add an attribute (for example mvirtualdata); select text filed adjacent to attribute name by clicking on it and press enter button once (or several times), then go under derived attributes tab and you'll notice that have been added as many derived attributes as times you pressed enter button.