Amazon Machine Learning Engineer interview questions

An onsite interview. I found the interview very bias and I faced discrimination because all the interviewers were from the same region, and I was asked if I on Visa or a Greencard holder during the interview process by one of the interviewers. Before answering her, I asked her if it made a difference and she said that she will pass me if I was a Visa holder. It seems that since a lot of companies had a layoff, a lot of companies are hiring visa holders than American Citizens/Greencard holders. There definitely needs to be an investigation on why major tech companies like Amazon are hiring certain people from certain regions.