Amazon Systems Development Engineer - Special Projects interview questions

Recruiter reached out to me for role in Special Projects team. Job Description hardly matched to what I currently do but she mentioned that the hiring manager is interested in talking further and since it is Special Projects, most info cannot be disclosed Got the first technical screening interview scheduled. It started with standard Amazon STAR based questions. He further asked Linux/Unix/Networking questions and there were hardly any questions which I couldn't answer correctly. At the end, there were three questions/problems in the Coding challenge. I got all three of them but took some time to think/complete the last one. I thought I did well but got the rejection email the next day, reason which is best known to Amazon