I have no idea why I got two LUDs. I just happened to log in my USCIS account and found the first LUD. Due to curiosity, I logged in again the second day and found second LUD. So far, nothing has happened to me yet, I mean for approval. No matter whatever reason it is, I think I need luck now for processing the case or for speeding up the process.
For your interest, I work on nanofabrication and nanofluidics.