Mom no longer has interest in TV and can't follow a program. Have any of you experienced this?

Very common. I would let it go.

My LO talked into the car radio thinking she was having conversations with dead relatives. So I’m not surprised your mom thinks she can talk to person on TV.
Pretty harmless though.

This seems to be a common problem with dementia and the television set. Check out this thread on the subject:

https://forum.alzheimers.org.uk/threads/talking-to-the-tv.15960/

Best of luck!