Appitsimple interview questions

Pretty disappointing. The JD sent by the HR team had a list of roles and responsibilities which were carefully read and understood. During the interview with multiple people I specifically answered the questions relevant to the job role. After investing over a week and several hours with the hiring teams, I was not selected. The feedback shared was totally irrelevant. The HR team says that the experience that I hold ain't enough/overqualified. The work I do is not into Customer Success but support. And the last feedback was more funny as they said the role they are hiring for is different of what was mentioned in the JD. Now my question is from the first day of the application, my resume mentioned my experience. Why was I taken forward to the next rounds? Second after almost a decade of experience in customer success, the concerned team is telling me that I have worked as a support function. Thirdly and most important, if a JD mentions certain responsibilities, the candidate ideally should/will align the interview to its relevance. It is frustrating to learn that the JD does not mention the requirements the company demands for. How can you expect the candidates to be relevant.

Interview process is fairly easy and consist of 2 stages. 1 basic round with manager. 2nd final round discussion with CEO. It a startup so they don't follow tradition HR way of hiring.