Lutron Electronics Software Engineer interview questions

Started with an on campus technical interview. Got a call for an onsite a few days later. For the onsite they had me prepare a presentation on a project I've worked on. The onsite consisted of a technical round, role-play round, presentation, technical round and 2 rounds with management.

I had a phone interview with a Senior Software Engineer in Philadelphia. She asked me a version of the FizzBuzz problem, had me implement it in 5 ways, I was able to answer all the questions as I was very much prepared. It all went well, she looked impressed, told me a little about the next steps. So the negative part is, I got a reject right after 3 hours of my interview on the same day. It was a huge disappointment. No idea what they're looking for.