Strategy Risks Open Source Research Analyst interview questions

I applied online, and was contacted on the same day, 5--6 hours after I had submitted my application through their website. I started my first of 3 Zoom interviews a week after first contact. When through all 3 interviews, no problems. I was told that nothing but positive feedbacks. I was expecting to interview with their CEO but 2 weeks after the 3rd interview, I failed to hear back from their staff to schedule that 4th (and final) interview. I reached out to them 4 times via email to see what's going on. Silence. No even an email saying "you're rejected" or "please give us a few days to get back to you." Nothing. It's been 8 weeks+ since last contact. I've sent emails to the 3 interviewers I talked to, but never heard back from any of them, even after 2 or 3 follow-up emails to each. Unprofessional, unethical, and should be avoided at all cost. The people were nice enough, but their interview process is alarming.