VKB-SIM

yes the locking screw was the first thing i checked, like you said i confirm for my side was just the need for more break in.

Sadly i can't reproduce the issue anymore because now center flawlessly so i think i fxed that just doing some full twist right to left and left to right without stopping in the center at moderate speed, so i presume the issue for my side was the grease maybe not well spreaded.

I have two kosmosima, the right is perfectly fine and the left started showing the same issue with the same behaviours as your but only for the left twist action like full/medium left twist doesn't center and small left twist always center.