Video playback is sometimes zoomed

I just upgraded to krypton and now when I play some movies, the video is zoomed in. Other movies are fine, and the menu screens are fine too. It seems random as to which movies are zoomed in. When it is zoomed and I pause the movie, I cannot see the time duration at the bottom. I can go to the menu options while paused and change the video resolution under the system settings, and the video goes back to normal until I exit out of the menu so the only thing on the screen is the movie. That is when the screen goes black for a second and comes back zoomed in. Any ideas?