how to select and drag to move text in writer

since upgrading to Libreoffice 5 I can’t select and drag text in writer

I’m new to LibreOffice, using Sometimes select-and-drag works as expected. Sometimes it works but appears not to, because the screen doesn’t automatically update (until, say, I scroll up and down again so that the moved text moves off-screen and back again). Specifically, dragging from one line to another seems to work okay, but dragging from one point in a line to another point in the same line has the display problem. I presume this is a bug.