I've had this issue as well (all saves) and have tried everything you've tried, too. Time wise, I want to say it's been since the movie hangout SP game out, but my remembering could be fuzzy there. For me, it's more of an annoying glitch. Can be worked around ---choosing same channel that other sim is watching, but it's a bit tedious.
I've tested @gohoneyrose save game but I'm not sure they sent me the right one and the haven't gotten back to me.
I was not able to duplicate the save I was sent.
Would you upload one of yours too ?
Just wanted to add that I've also been having this issue for some time, probably since the movie SP patch like a previous poster said. I do use mods, but the issue doesn't go away upon removal of them or even after a total game reset.
For all of your TVs ? Did you start a new save game on a vanilla game to see if it's the same (for testing purposes)
