My little Timmy has this problem. I must mention he is not pure Chi .. but would say he is predominantly Chi. His ears are up and down and he is 12 months in one weeks time. So I'm losing hope they will ever stay up 'all' of the time. I love them up, he looks so cute. But they do their own thing. I tallied with the idea of sticking them up with tape when he was about 7 months or so .. but he hated it and just pulled it off. I 'think' they do respond to massaging .. but later will still go down again

.. here is a pic of him with them up.