crdmrn wrotethe constrained one just moves in a different way
How differently does it move? I notice you have all the sliders linked and at 100, if you only want the bone to match the position of the target, you could unlink the sliders and leave only Translate at 100, while moving the other 3 sliders to 0.
If this doesn't solve your problem, it might also be a problem of constraint order, constraints in your constraint nodes are applied from the first in the list, to the last in the list, which means that if some constraints look broken after a new constraint is created, it might be due to an incorrect order, and dragging the broken constraint down in the list to have it applied after might solve the problem.