Over the last two days; there has been improvement. I still experience one or two episodes of stuttering and/or screen going black. There was a suggestion to reboot the router and then reboot each tv’s “receiver” which I will try to do this weekend.
I switched to Rogers in December because Bell can only offer me 50mbps Internet (my house is too far away from the demarcation point). If these problems continue with Rogers TV Ignite, it will give me the time to research "cutting the cord".
Here in Kitchener, the problem still exists. The stuttering and the black screen to the point of unwatchability seems to occur most of the time in the evening. The next morning the problem disappears again.