Those are two different names. Are you stating if you have two copies of Nightmare On Elm Street, you can't get either to run? If so, why do you have two of the same movie? have you tried a slight re-name, something as simple as adding a single character or number? I can see why that would confuse the system, I'm surprised that you were able to add a second entry of the same name in the first place.
Yes this problem is very annoying and needs fixing. The scraper can’t handle the year of the movie in parantheses so thinks they are two versions of the same. Other scrapers like Zapppiti, Kodi and Dune can handle this so you get two unique versions of Cape Fear, for example, not one version with A and B incorrectly sitting under a single poster.
