Are you certain? Japanese is like any other language, and has regional accents. I seem to recall my sibling's Japanese professor (a native of Japan herself) explain that whether a person audibly pronounces the U in words like suki or not, that it reflects where they were raised.
Duolingo teaches through trial and error: the most positive way to learn anything. And after you errored out you were shown the correct answer, right? And now you know it, correct? You are on to it and have mastered it now, that not so? If so, then what are you crying about?