"George A." <email@example.com> wrote in message <firstname.lastname@example.org>... > > Thank you for this Matt. > No the bounds are the same in both cases [0,inf], and the tolerances as well ===============
OK. Well, it could be happening for purely mathematical reasons. Consider even the very simple linear scalar lsq problem
min f(x) = (a*x)^2/2
where a=1e5. Then at x0=1e-8, the objective function is quite small
f(x0) = 5e-7
but the first order optimality measure, i.e. the derivative, is 100....considerably larger.