Reply To: InDesign CC 2017

Hi there, this is my first post. Since upgrading to 2017, I’ve had a seemingly random thing occur with some of my text frames: sometimes, while in Type mode, one of my frames and its handles will turn solid blue (even while typing) during Preview when I press ?S. It only happens to one frame at a time, and it remains visible whether my type cursor is active within that frame, in another, unthreaded one, or when any text box is selected. It disappears when no text frames are selected, then reappears when any one is selected again. The only way I can get the blue frame to disappear during selection is to hit ?A for the text inside the frame in question. Do you know why this is happening or how to make it go away?

Thanks in advance!