ASML Mechatronics Design Engineer interview questions

1st step was technical round with recruiter on call, very easy mostly questions from resume. 2nd round was technical with 5 senior technical heads, again questions about past experience such as tell us about you. After that was called on-site interview with 30 mins of the 2nd round. During Onsite I had an interview with 8 people however now I was suddenly given very difficult questions, some were nothing to do with the position I was interviewing for. got a reject in 3 days no clear reason why. The onsite was suppose to be hr according to the recuriter. Why confusing and misleading.