Ask someone for feedback to see how you are coming across during your interviews.
Remember that if you have been invited on site for an interview, you were hireable until the moment you stepped on their campus, assuming they had a real job opening.
Companies simply do not have the resources to allocate a bunch of people to interview a college student. It costs them a lot of money to set up an interview. So you have been a viable candidate. It is possible they are simply finding someone better or did not find you compelling enough.
3.9 GPA in engineering is an amazing asset. You need to exude positive vibes during the interview, have very accepting attitude - can you do this - no but it shouldn’t take me too long to learn - look at my GPA - I work really hard and I can pull my own weight. I contribute a lot more than my share to my group projects.
Lastly, no one is taking your job. Workplace diversity requirements are quite common in large companies. OTOH, nepotism and contact driven indirect hiring is common across board in every work environment. Be positive and assume that you can get this job when you walk in and someone will like you enough.