It would have been a great addon if it actually worked.
Anyhow, I like to repeat what people already said earlier:
First: There is a "?" sign on the single displays instead of showing the score, no matter which score engine one chooses.
However, secondly, you are able to see the scores on the displays of "Netflix Originals". Maybe because these are queued differently in a bigger format.
I hope my explaining here helps to fix this issue soon since I'd love to have access to the imdb ratings.