I tried to find the root distritubion of a polynomial?

When p=1, q=3, the following command works.

with(plots):

eq:=u^(2*q)+1-2*K*u^(q-p);

p:=1; q:=3;

unitcircle:=implicitplot(x^2+y^2 = 1, x = -1 .. 1, y = -1 .. 1, scaling = constrained);

animate(complexplot,[[solve(eq, u)],style = point,symbolsize=10,color="red"],frames=50,K=-1..1,background=unitcircle, scaling=constrained, trace=20 );

However, when I tried p=2, q=3, only one root was shown on the animation.

But "complexplot([solve(eq,u)],style=point)" showed 6 roots anyway.

I have no idea what was wrong.