Metal head attachment & metallic driver rotated resulting in noise

My Sonicare was suffering from one of the usual problems that the magnets and the metallic driver were too close and I had to increase the distance between the two (see description here) which was a rather easy fix. I have also ordered a new metal head including the plastic parts to again have a properly watertight toothbrush.

However, there is one remaining issue which results in a lot of noise. The triangular shaped part where the metal head is attached using a screw is rotated as shown in the image below (red arrow points to rotated triangular shaped part):

This is due to an issue "lower down" in the toothbrush where the metallic driver (blue arrow in image below) - which is directly connected/linked to the above mentioned "triangular shaped" part - is rotated as well.

By forcing quite a bit I can rotate it back to "normal" position, however, as soon as I switch on the toothbrush the whole thing gets stuck again in the rotated position.

My two possible explanations so fare are that a) the magnetic force in the two magnets has somehow changed which results in a rotation or b) there was some abrasion or similar on the surface of the metallic driver which results in this rotation.

Any ideas on how to fix this would be highly appreciated!