When I have experienced less eye contact than "usual", it seemed to be about my T thinking hard. She usually focuses somewhere else than on me when she is thinking.

It would be good to talk to her about your feelings about this. She is looking at you less, and you are experiencing it the way you experience it (the way we all experience separately). Much to explore - is she even aware she is making less eye contact; does she say there a reason T is doing this; is this something about how you feel connected/disconnected and that internal process; what does making less eye contact mean to you, etc.