Interview Report: LinkedIn

I recently had a Zoom interview with LinkedIn. It was 1-hr long. The interviewer spent 40-mins into behavior questions and in the last 20-mins pasted the MaxStack (LC Hard) into CoderPad and asked me to implement all 5-methods. I knew the problem so it wasn't an issue for me, but I tried to strike a conversation and wanted to make sure that I understood the problem correctly. The interviewer wouldn't speak a word or engage in any conversation.

After I write the perfect MaxStack that I can write with my eyes closed, the interviewer wrote in my feedback that my code wasn't appropriate! I am seriously lost at interviews now. What is the expectation these days?