@srcarroll -- you should contact Rogers/Shaw, and get them to check the "signal strength" reaching your TV box. Ask their Agent to remotely logon to your box, and see if you are getting a weak signal. Such a weak signal can cause the video-feed to be "intermittent".
But, before you call, check that the coaxial-cable between the coaxial socket on the wall and your TV box (or cable-modem) is tightly-connected at both ends. Also, try a different cable. Also, try a different cable between the TV box and your TV. If your TV has multiple HDMI inputs, try connecting to the other input(s).
When the technician arrives at your home, they can do more "physical" checking:
- up the nearest telephone-pole,
- their cable from the pole into their "demarcation" box inside your home
- the "coaxial-splitter" inside their (locked) demarcation box
- the coaxial cables inside the walls of your home
to try to remediate. There is no charge for this "site-visit" -- they want to keep you as a monthly-paying customer.