Trimble R D Engineer interview questions

I interviewed with trimble in march 2021 for R&D position. HR contacted me for intital discussion where I told my notice period is 2 Months in my existing company. He said okay and we went ahead with interview process. There were 6 rounds in total 4 pure technical based on DSA, design and real life problems what kind of data structures I will choose. 2 managerial round, 1 was basic managerial about why I want to work for trimble and other one is home task about real life problem which trimble is working on. I cleared all rounds and then HR called me back saying they want a candidate who can join them early, so my profile is on hold as they are considering other candidates who can join early. This is like a scam if they wanted a early joiners why they wasted my time as well as theirs, this shows they don't care about good candidate who cleared a hectic interview process