I am working on a small project. An elliptic curve equation with y^2=x^3-3x+27 mod 43, a point $Q=(1,38)$, using point doubling method https://en.wikipedia.org/wiki/Elliptic_curve_point_multiplication#Point_doubling, i got $2Q(Q+Q)=(41,5)$. Now in projective coordinate $Q=(1,38,1)$ taking $z=1$.https://en.wikibooks.org/wiki/Cryptography/Prime_Curve/Standard_Projective_Coordinates
Calculating $2Q$, I get $2Q=(22,31,39)$ and converting to affine coordinate I can't get $2Q=(41,5)$.
So, where did I went wrong can anyone explain or am I following the wrong method??