and was at the time of testing?
If the trans was mine, and already or still, on the bench, I'd be taking it apart. But if it was mine, I'm reasonably confident that it wouldda never come to this.
But since I'm not there to judge the turning effort,
which to me; "it will turn only one direction in neutral" seems excessive,
I can't recommend that YOU take YOURS apart. Like those before me have agreed upon, and your inspection showed, it could be and/or probably is, normal.
But just to reiterate in stronger words;
I have never had a TF that would not turn at all, in reverse rotation.
Well unless it was in Park, lol; but then, it wouldn't turn at all, lol.