Audio sync problems on new Contour box

We just switched out our contour box for a new one as the old one completely stopped working.  We plugged it in and set it up but there was no sound.  We tried resetting the box but still no sound.  I tried a different HDMI cable and I have sound now but it not synced with the video.  We've tried refreshing the box with no luck.  We did not have this issue prior to getting the new box.  

The severity of the sync problem varies.  Sometimes its only slight and barely noticeable and other times its quite off and very noticeable.  The issue happens both when watching cable, and when using the Netflix app though cox or watching on demand.