Thanks to all for the fast replies!
@David
If I understand correctly, I have to increase the idle current M906, not M916 (stand still current). I will try out this with the M906 in the config.
@Mrehorstdmd @DocTrucker
I will try this, if that with the M906 doesn't work.
Thanks again for your help.
Incidentally, I am Swiss and live with my wife in Malaysia. My English is not good so my wife does the translation. Because of the time difference, it may take a little longer for my answer.
here is an image of my 3D Printer. The wiring and finishing work aren't ready now.