thanks a lot for your answer.
Yes, I think it is the shape of my oral cavity.
With all other (unbent) draws, it is more like ‘Ta’.
With the 2 draw, I either need to breath in through my nose (so, less air flow through the harp), or make the cavity smaller, like saying ‘Tee’.
I don’t think it is a technical issue with the harp because I’m having the same problem on two C harps.