Brief video freezing on ESPN channels and AAC Network, but not on SEC Network on my secondary contour receiver

ESPN channels and the ACC Network work fine on my main (DVR) Contour receiver, but I get brief video freezing on my secondary (small) Contour receiver on those channels.  It’s very annoying, especially for watching games, and it happens periodically in both live and recorded programs, but only on that TV using the secondary Contour receiver. The audio is doesn’t skip, just the video.  I have checked the connections for tightness, but I’m thinking I may need a signal boost to that secondary Contour receiver.  Anyone else having this problem?  Why only sports channels, but not all sports channels. SEC Network appear to work fine, I think, but I haven’t checked recently. Thanks!