Distorted signal between set-top box and TV

About 6 months ago we bought a TCL 4k smart tv.  We were still using our old MOTO DCX3400 (?) DVR (no X1).  The TCL is a Roku TV so has its own home screen.  One icon/tile is for the DVR which is just a labeled HDMI input.  About 3 weeks ago, while watching live tv or a recording, the screen would start getting 'snow' and within seconds the entire screen was nothing but static.  We were planning an update to X1 so didn't worry about it.  A week ago, we made the leap and are running an X1 set top box.  Same exact issue.  We've since discovered that pressing the home button on the TV remote to get back to its own 'home' screen and going straight back into the DVR would completely clear the static.  Obviously an issue with the signal between the set top box and the TV.  Perhaps it's an issue with the TV since it happened with both set top boxes.  But, figured I'd start here to see if there's a signal strength issue or something related.  Thanks in advance.