J.B.
We had the exact problem when I brought my son home (he was born at 29 weeks) with the bassinette. I eventually had to start playing soft music and leave a light on all night (with a cover over the bassinette to filter the light; I just put it over the hood and laid it gently over the rim so that he could get plenty of air but the light was filtered) and it worked incredibly well. I called my NICU nurse and asked her the same question you are asking here and she said that since babies spend so many days in the NICU they need a lot of light and noise for the first few weeks after coming home in order to sleep. I slowly weaned him off the light after about 1 week and he was fine with just the music and then after about 5 months, I weaned him off the music and he slept perfectly. Good luck!