Rocket III Not-So-Uncommon problem | Floppy or Stuck Shifter Lever

A simple bolt in the shifting mechanism can come loose, due to the threadlock adhesive being applied incorrectly in the factory.
This results in a floppy shift level, which will not change gear. The shifter can get jammed also.
This is different from the 'detent spring' problem, where the manifestation is the bike won't stay in gear, but the shift lever still works.