F5 Software Engineer III interview questions

I reached by an H.R in linkedIn. Then I submitted my application for it. Received a mail from H.R for the first round of interview where I gave a brief introduction and my past experience roles and responsibilities. Later on, I had an interview with the director. All went well I got some positive response from Director but after a week I got a call stating I got declined. Overall process went very smooth. I wish response time should be reduced a little.

The interview took around 2+ weeks via zoom. First there was a Hacker Rank test, then a Technical round 1 (On standard DS algo questions related to linked list, strings, arrays ), and followed by a Cultural Fit round, then a Technical round 2(again medium level questions on ds algo and some random questions on networks, C etc) , and then Hiring manager interview (questions related to experience, debugging, virtualization, networking) and he started asking puzzles (which i didn't expect). out of 2 questions on puzzles I couldn't answer one and for the second one I said the approach. But i felt the guy has poor communication and soft skills though he might be technically good. I couldn't properly understand sometimes what he is actually asking or saying due to improper sentencing and was very hurry to point out mistakes than the usual way of guiding. I didn't get any response even after two days and then I followed up with HR. He emailed saying we can't proceed further. I saw some other people experiences in glassdoor and it was same. They were been taken through all rounds but at the end they were rejected. Sad that they are wasting peoples time.