Documantation for setDynamicLayout():
     * On platforms where dynamic layout during resizing is not supported
     * (or is always supported), setting this property has no effect.

Documantation for isDynamicLayoutSet():
     * Note: this method returns the value that was set programmatically;

Documantation for isDynamicLayoutActive():
     * Returns whether dynamic layout of Containers on resize is
     * currently active (both set in program
     *( {@code isDynamicLayoutSet()} )
     *, and supported
     * by the underlying operating system and/or window manager).
     
So according to documentation "set" method can be ignored by the native system, but isDynamicLayoutActive takes into account isDynamicLayoutSet(), which always return value which was set.