The images show it all but the display of 'Level' of the effect and 'Duration' are the wrong way around.
The big image shows I've given myself saturation level 10 for 0 seconds, you can see my player received exactly what I wanted but the message displays I've given myself saturation level 0 for 10 seconds.
Unless I'm missing something here, both images say
What's the bug? I don't understand.