GHD Environmental Engineer interview questions

After applying online I interviewed with HR, then had an in-person interview with several PMs and my peers. The interview process was very laid back, pleasant, and fairly straight-forward/easy. The people I spoke to were wonderful and kind, very easy to talk to... which is why I was stunned to never hear back after my third interview, despite multiple requests for updates. I contacted HR as well as the PMs I interviewed with for any information in the following weeks and never heard back. I don't understand why I was ghosted as they refuse to speak with me in any manner. Very unprofessional and unfortunate; it really makes no sense to me as the people there seemed so kind.