My player Fischer was DMR/MR/AMR and became a DR after the update. Because I was playing 4-5V-1 I needed an AMR who scored and Fischer wasn't providing the job even after SS SA, so I got a new AMR. Luckily because of the new position I decided to keep him as a backup DR with Terrible results, he wasn't that bad in DMR position and actually shined in MR. I do believe that players perform better in some positions than others.

The thing is the game is so unfair to defenders and the GK in general. A clean sheet should reflect somehow positively on the ratings of the defenders but no, defenders are rated by the same standards as attackers, when a defenders scores, then he will see an increase of the rating. Also defenders get less experience skills than attackers on average.