Hello Alan E:It may be as simple as that the fromt port brings the dongle in a more direct line wiht your router, or the rare port has a bad connection.
Aldus, the turn of the keyboard message comes when the keyboard is having problems reading a file, or when we work too fast, so the keyboard don't get enough time to keep up. I get that message on all my keyboards from time to time. it is not a fault, but rather the keyboard's way to protect itself.