The hidden error

I have completed the animation of the elastic collision
https://www.geogebra.org/classic/hxvcaphh
and the inelastic one
https://www.geogebra.org/classic/atdrbrse
where, in both cases, I noticed a strange phenomenon.

In the inelastic collision, body A with mass m_A=1 exerts a force
F_AB=+v on body B, because it increases its speed from vi_B=-v to
vf_B=0.

Wanting to double the force from F_AB=+v, to F_AB=+2v, I would
spontaneously do so by doubling the mass of body A from m_A=1 to m_A=2
(which in the animation I can vary with the appropriate button).

And instead, this doubling of the force does not occur because with the
mass m_A=2, the force does not double from F_AB=+v to F_AB=+2v but
limits itself to increasing only up to F_AB=+4/3v, which is less than
+2.

And the same thing happens in the elastic collision where, when the
mass of A doubles from 1 to 2, the force increases only from F_AB=+2v
to F_AB=+8/3v and does not double until F_AB=+4 (which is double
F_AB=+2v).

Why does the doubling of the mass not also correspond to the doubling
of the force, if the speed is the same?

Evidently, in all this there is some hidden error: what is it?

Luigi Fortunati