-- is that a recessed area in an outside wall? Is it a so...

[mdk]

@AlexPeekay -- is that a recessed area in an outside wall? Is it a south-side wall, that is getting more solar-heating than it was getting during the September-to-March "winter" in Victoria? Is the ambient room-temperature now warmer?

Have you tried fully-disconnecting all the cables from the Shaw box, then taking a can of a compressed air, and blowing-out any dust that might have accumulated inside the box? The dust could be acting as a "blanket" that is keeping the electronic components warmer.

[mdk]

@ziggurcat -- I can adjust the volume, but I cannot get into the guide or settings right now.

I presume that you have synchronized your Shaw remote-control to your specific TV. 

Thus, some buttons on your remote: on/off, volume up/down, mute, source send signals directly to the TV,

while some buttons: guide, play/pause, rewind, channel up/down, settings are sent to the (non-responsive?) Shaw TV box.

So, your description makes perfect sense.

[ziggurcat]

The signal had returned at that point, so the guide/settings buttons should have been responding.  I had to unplug/plug the unit back in to get it to work again.

[9036]

I am having the same issue / I just got the new boxes and it is happening in both of my tvs