I saw a video by David Pogue, showing how by deep pressing while editing text, his phone went into what he called "trackpad mode". The keyboard blanked out and he was able to easily move the curser around to edit. When I try to do it on either my wife's iPhone 7 or my 7+, it just opens a magnifying glass like always. Does anyone know if there is a setting that might prevent "trackpad mode" from working?