I have the same problem, and my laptop modle is Probook 440 14 inch G9, my colleagues met this also, It seems like not an isolated case, but I’m not sure what keys triggered it because of fast type speed,,,I kind of agree with the poster. And I don't think it was electrostatics caused it, this model does have electrostatics sometime, but there's no electrostatics on the enclosure when the problem happens, maybe electrostatics inside the keyboard??