I have a young defenseman who was a RD and I always train them to learn LD and vice versa.
He did learn but he always complains.
After he learned LD, I change him to a standard Defense that I edited.
He hates that.
I then created a Light workout.
He hates that.
I tried him at LW thinking maybe he hates defense

He hates that too.
I guess next stop is resting.
This feels like a bug that a player would essentially reject all forms of training.