NIPT testing with a vanishing twin???

Heather • Mommy of 💙💓💓💓💓👼👼

So at 8+4 I found out one of my twins was not going to make it. I was warned that it can cause false test results and gender. If a baby boy died and a girl is surviving it could give a false xy for a boy. Has this happend to anyone before what was the outcome ??