He does not sound like a good friend. It sounds like you've had a mix of experiences with him, good and bad, but because of that, you are rationalizing his behavior. That's not okay behavior and it IS mean to say "You're boring me. I'm muting you now." My advice would be to not message him and just move on. Especially since he is generally rude and inconsiderate. I would not be friends with someone like that, but that's just me. Or, if you want you could message him one last time, checking out your feelings, like you want to, and then if he doesn't respond (which is rude, mean, etc) because he has you on mute, etc, or is just a jerk, forget him. I get the sense that you may have low self esteem? You are worth much more than a friend who acts this way! You deserve to be treated well in your friendships, we all do.