Took another stab at it, and you should know that the App will update the CPU usage, but the intervals in between updates are quite a bit longer than in the web interface. Another thing that could lead to the impression that nothing is changing is the fact that according to your screenshot, the max CPU usage in the time frame of the graph is 0.10%. The display will only show up to two digits after the comma. It is possible that the change is in the 3rd digit only and thus gets rounded to the next 2 digits which can lead to the impression that nothing is updating.