XB8-T causing tiling on TV

I'm not sure if this problem should be posted here or in the Internet forum. I'll try again is this is the wrong place.

We have been having serious tiling issues with our cable TV and after tightening everything have tracked it down to the XB8-T gateway which we installed maybe 6 months ago. When we disconnect the gateway, the problem goes away. Looking around online, it seems this has been a problem with this gateway for several years. I'm up for any suggestions for resolving this. Will replacing the gateway make a difference? Is the XB10 available in our area? The TV has become unwatchable recently. Help is much appreciated!