Panmure Liberum interview questions

PL were hiring through Carter Murray and so my direct point of contact was Carter Murray first. I was informed they liked my CV within a day, then I heard nothing for about a month despite chasing. They then called me in for an 'urgent' interview because the person they wanted to hire failed background checks. There were 3 stages - screening with Carter Murray and 2 with Panmure. I was first interviewed via Teams and that lasted about an hour - it was quite informal compared to other interviews I did. I was then called in to do a 2 hour interview session with 3 different heads - head of HR, head of Marketing and head of Research. After all of that, they gave me great positive feedback only to tell me they want to interview one more person. This was Wednesday and over a week later I found out, by calling and emailing the recruitment agency, that Panmure decided to go with the other candidate. I was given no explanation even though I asked for feedback twice - not to argue my case, as I wouldn't want to work with a company after all of that, but to see where I did wrong. Overall, very negative experience compared to the few others I have interviewed at.

It was a technical interview with a comprehensive stock pitch expected. Alongside competencies and motivational questions. Usually 30 mins long and time at the end for questions and it was two people, one from HR, interviewing me.