It's conceivable for your sound to move ahead of the screen on your TV if your Skybox/disc player/TV box is connected straight to your soundbar. Many current boxes have a function that prevents this from happening, which you can locate in the audio settings menu.  Search for an option on the box named ‘Audio Delay' or something like that's causing the issue, then tweak it notch by notch until your audio and visual are exactly in sync again.