NIPT redraw/Early SneekPeek result?

Hey ladies, so I am highly confused on how I should interpret this situation. I had the sneak peek gender test done at 8 weeks and the results came back Boy. I just went in last week at 12 weeks for my NIPT test and was told by my doctor today that the I will have to go for a redraw because there was not enough fetal dna. I do have a higher bmi so after reading that could be what caused it, but my question is how did Sneakpeek determine the gender if the NIPT couldn’t at 12 weeks. I am now anxious to find out gender since I was told a boy, I know it is not 100% but I kept being told it’s highly unlikely it was wrong. 🙄🤷🏾‍♀️