Reliable Robotics interview questions

Multiple rounds of technical questions, leet code did not prepare me well. Unfortunately, the questions are not boilerplate software questions you can just study for a month and get the job.

I had a web interview with the FPGA Team Leader. Seemed to go well, he just asked about experience and background, told me about their company/systems. He asked a couple very beginner FPGA technical questions. He then spent a significant amount of time (unprompted) describing how the rest of the interview/hiring process would go: the next phase would be a take-home mini project, then fly for an in-person interview. He discussed the onboarding process and relocation options. We discussed start dates and timelines. Salary was not brought up. Less than 24 hours later I received a rejection email. I asked for feedback since it seemed strange to get rejected soon after a pleasant introductory interview where all signs pointed to moving forward, but was ghosted instead.