Prisma Data interview questions

There was a take home assignment, and in the next round we talked about it, with additional technical questions. The interviewers were knowledgeable and tried to help and ask questions until the right answer.

Went through an initial interview and then was given a task which required hours of work. Had another interview walking through the task where I got no feedback. In my rejection, they mentioned they would be happy to provide feedback. I followed up multiple times, but never heard back. No idea what went wrong