i9515: compass not working properly

Hi,

I am very disappointed by the compass quality of my i9515 S4 value edition, because no matter what I do, whatever direction I turn my phone to, the compass only changes by about 2 to 10 degree, and has the wrong direction most of the time.

This is Android 5 stock ROM.

I have made a video to illustrate the behaviour.

http://youtu.be/g6jcmLf8L3A

What I have tried:
- enter the calibration dialing *#0*#, which passes, but does not change anything
- reboot
- try different compass apps
- switch of energy safe mode

Nothing helps. Is this a general bug with the i9515, or is my compass sensor broken?