MANTECH Systems Engineer interview questions

Email and phone call with recruiter, HR phone screen, phone interview with team lead, followups with recruiter over phone and email. No in-person contact until I had signed an offer and noncompete (this was still Covid-era). Critically, they never countersigned the offer, and in fact retracted the offer after an in-person meeting that was pitched as "meet the client and get up to speed" but was actually more like a secret bonus interview. At this meeting the client mentioned that my team lead commonly "keeps prospective employees on ice" by dragging his feet on countersigning their offers. The client did not ask many questions about my previous work (which was quite well suited to the position), but nonetheless determined I was insufficiently excited to work on his project and lacked an innovative attitude. Had I known this was an interview and not an initial meeting, I would have been less reserved and tried to showcase my skills and background more. I found this practice of delaying countersignature and deceptive meetings wildly unprofessional.