Classplus Senior Software Engineer Backend interview questions

The interview was rescheduled multiple times with no prior intimation. That is not a significant issue, but later on, the interviewer was utterly uninterested when the second round was scheduled. He asked basic questions and asked me to solve a problem and showed no interest in understanding the solution. Somehow he wanted to get done with the process, minutes after the interview, I get a message saying I am not a suitable candidate for them.