Cisco SRE/DevOps Engineer interview questions

Very confusing interview process first they had 1 round with the manager for 30 minutes then after that 2 tech rounds 1 round was with us panel of 3 people i have answered all the questions but got rejection mail , i was like okay then HR calls me and says that was an automated mail which was sent via tool ignore it 3rd round ) once again a panel of 2 as i was saying answers one of the interviewer was rolling eyes (why dude ?) after that no response i called the HR she said that they have selected another candidiate and put the job on freeze . got rejection mail if you had to reject me why to take another round for no reason ?