Yes, but did you unplug it and blow in the connector? 😉 Old trick to make sure the person on the other end of the phone does it and does not just say they did it, give them something to do.
Is the box connected directly to the TV? I had a problem where my receiver (a Denon) developed a problem on it's 4K inputs. All sorts of problems that I thought was Rogers but turned out to be the AV receiver. I switched to non 4K inputs (older model, only had 1 4K) and it works fine. I cannot get 4K at all using that, but I never watch anything in 4K.
Is the Wifi signal strong on the box? Can you try it wired, even just to test?
Oh, I know all those tricks, Don. This old dog's been around the block a few times...
The box is indeed connected directly to the TV. I have a sound bar connected to the TV as well, via digital optical cable. I suppose I could use an HDMI cable and the sound bar's ARC connector, but I've always believed optical provides the cleanest pass through sound.
WiFi signal is very strong. The TVs are the only devices connecting/using the SSID from the Gateway; I have a discrete mesh network running off the Gateway's ethernet port, and all the computers/phones/doorbells/toasters in the house connect to that SSID.