Fit! interview questions

I applied via email. The initial phone screen video call was also a technical interview. The interview was uncomfortable. The interviewer did not turn on his camera throughout the interview, asked overly specific questions about Redis, and then had me do a live coding exercise that was a leet code easy. Afterwards he told me that he was going to green light for the technical interview. He then proceeded to tell me that i "needed to work more on my algorithms" and I was to spend one month studying algorithms before my next interview. I asked if the next interviews were technical. He said no, they are cultural interviews. I told him that this was unacceptable and I would not be continuing the interview process. I I don't know what their angle was (presumably a stalling tactic), but the interviewer came off as insulting and lacking transparency. I have never been told before that I passed an interview and then told I need to study more. Nor have I been told before that the interview process Should wait for an entire month.