Isar Aerospace Test Engineer interview questions

I applied online, and they returned in two weeks and provided three engineering questions. After I replied, HR started an interview process. HR was mostly neutral during the interview and asked very general questions. The following day, I sent a follow-up email and HR replied "Due to available capacities, we have decided to fill the position internally and therefore close this job opening." Probably the position never existed, Bad experience and only time-wasting. I recommend not spending that much time making applications to them and their questionnaires.