Elliptic curve point multiplication — who is wrong?
The (very useful!) computer algebra system sage says the correct result is indeed $(6,14)$:


sage: E = EllipticCurve(Zmod(17), [2, 2])
sage: E
Elliptic Curve defined by y^2 = x^3 + 2*x + 2 over Ring of integers modulo 17
sage: P = E(5, 1)
sage: 891 * P
(6 : 14 : 1)



Those "online calculators" you used appear to be broken.