Hi
That is a little weird, hopefully there are no problems with it. Have you drawn it to full draw? If you're going to, I'd try to 'heel' the bow a lot so that the bow's drawing pressure is on the lowest part of the grip. - that's what I'l ltry to do with my hornbow that has a significantly weaker limb.. it'd put more of the pressure on the lower limb afaik
Usually, in general (not Korean archery?..) the stiffer limb is the bottom limb, and the top limb has the be a bit weaker. So I think it's better that the weak limb is the top limb in this case..
I think it could be the way you brace it. Especially since it's bamboo, it might have a bit more plasticity or elastic memory (like a hornbow) at the beginning, so you could try to bend the lower limb alone more, on the knee, as if you were trying to balance a hornbow. And when you string it, try to apply equal pressure to both limbs.
I don't think the tiller is too far off at all. Notice any cracks on the bamboo?