Twice the mass is twice force twice the acceleration. Gravitational force is linear to the mass of one of the objects. It would be 19.6m/s2 if the radius was the same but the radius is larger and that’s inverse quadratic. Double the radius, quarter the acceleration. Although I really doubt that planet is only double our mass.

2.6x the radius of earth, 8.63±1.35 the mass of earth.