Boeing is being sanctioned by U.S. investigators for sharing information about a federal investigation of a door plug blowout that left a gaping hole in a Boeing 737 Max 9.The National Transportation Safety Board said Thursday that Boeing “blatantly violated” the agency’s investigative regulations as well as a signed agreement by providing non-public investigative information to the media and speculating about possible causes of the Jan. 5 door plug blowout on a Boeing passenger jet in Portland,...