Thank you for the candid reply. A small part of dropping out was because it wasn't good enough, but I knew that even before joining. But in my first month of joining, 2 of the profs in the department moved to another university and there were no research opportunities even for 3rd years. 5th years were trying to postpone their graduation and in the last 4 years since I left, there has been 1 publication from the department in any of the finance journals. The school was ranked in the mid 80s when I joined in 2016 and now it has dropped to below 140 because of no work being done there. I have no regrets in dropping out and a big part of that decision was definitely the hope that I would move to a better department and do better work.
I did not drop out of the Masters program. I graduated with pretty good grades. A big reason for me thinking about another Master's program is to get some research experience and honestly I am hoping to beef up my application enough to outweigh my dropping out of a PhD program. Because like you say I know it is a red flag that is gonna need some explanations in interviews. But I do want to have an application that is strong enough to make it to the interview rounds. Hopefully that makes sense.
I also want to show them that even though I have been out of school for 3 years, I can handle the coursework and the research work required. And get more recent LoRs of course. But I agree with what you say. I am trying to weigh the benefits of spending time and money doing another Masters. I have been reading here that there are masters programs that have a track record of placing students in good PhD programs and I guess that's what I am looking for. If I can get into a good enough Masters program, then I would consider the benefits to definitely outweigh the costs in the long run.