VW shift adjustments have been like this for years. Seems like all non-beetles
have them. I never liked them. But it works great in the factory with new parts.
The splines on the shaft make a good impression on the adjusting sleeve and then
when the time comes to do an adjustment both parts want to stay in the splines.
If the adjustment we want is in-between the spines it just wont work.

Here is something I have done: Take the shaft out of the sleeve and with
suitable sandpaper try and remove the impression of the splines from the inside
of the sleeve.

Here is something I have thought about doing: Take the shaft out of the sleeve
BUT don't sand it. Then spread the sleeve open a bit, just enough so that you
can wrap a thin metal shim around the shaft and then get the sleeve to go back
in place. The shim gives you a new surface that the splines on the shaft will
bite into and the impression on the inside of the sleeve will lock onto. Next
adjustment replace the shim and get a new surface.