I'm not aware of a shift lever adjustment. But I have seen boot adjustment.
What kind of boots are you wearing?
My nephew who lives several hundred miles away started riding a few years ago. He had issues shifting and asked me what I was doing. I told him I do not have a heal-toe shifter and I have no issues getting my toes under the shifter of any bike.
Come to find out he was wearing his boots from when he was a fire fighter! He could not feel anything with those heavy boots let alone getting under the shifter.
So that was an easy fix.:biker: