Great program by the way - I did try restarting the session, screen still appeared incorrect (showed only in top quarter, I'm guessing proportional by resolution) and mouse did not move correctly.
Using latest 6.8.0.1 version - changing resolution on host while connected (and even after reconnecting) causes mouse tracking/clicks to work incorrectly - doesn't click in the right place, and screen no longer stretches to correct size. Win10 host & viewer.