UBS Software Developer interview questions

It is a disappointing interview process. The HR send me a link informing me that to prepare well and wearing formal for the interview, i.e. treat it like a formal office interview. On the interview day, one of the interviewers forgot about the interview. The interviewers are wearing casual on their end. They specifically look for Java skills only. It seems that the HR team and hiring managers did not communicate well in the selection process.