I've never experienced what seemed like a T bored with me in session, but with one of them I did have to repeatedly ask him in the beginning to engage more and make it more interactive, because that's what I like. I get very bored just talking and having someone listen, even if it is clear that they are paying attention. I think I would leave a T that showed lack of interest and engagement repeatedly, especially if they continue to do so after my telling them that I go there to interact with them.