why do desi interviewers behave like this

I recently had a full-time interview loop with a client in Dallas. The first two rounds went very well — both interviewers focused purely on technical topics and asked coding questions. The third round was different. The interviewer, an Indian man, opened by asking when I finished my bachelor's, when I finished my master's, and which consultancy I work for. Then he started scrutinizing my room and surroundings, claimed my audio was lagging, and opened the actual interview by saying I looked "grumpy" and had an attitude. He never asked a single technical question — he ended the call abruptly, accusing me of using a proxy, and hung up. Such a frustrating experience. He clearly walked in assuming I was fake from the start and never gave me a real chance. Completely unprofessional behavior.