Post MBA career - how to break into equity research

Dear Community: I am an MBA graduate working in PWM, and would really appreciate some advice on how to break into the equity research industry.

A short background about me: I started career in management associate program in a global bank, with a focus in wealth management. After finding interest in equity research, moved to a family office as a generalist investment analyst for a short while, and then did my MBA. During MBA, I was struggling with whether I should stick to my original career plan of doing equity research, since I got a return offer as a private banker at a bulge bracket bank. Eventually, I took up the full-time job, due to good pay and thoughts of "exposure to financial market and investment ideas". But on the job, I realized that private banker is a pure relationship building role, and wanted to refocus on equity research.

I have been applying to both sell side and buy side equity research roles for several months, but only managed to get one interview after applying to 100+ firms. Here's some reasons I could think about: (1) Lack of equity research experience and specific industry knowledge (2) Missed the MBA recruitment window (3) Too old for analyst role, but would be hard to find an associate role given my lack of experience. (4) Career seems quite jumpy and not focused.

In short, my question would be: given my background and age (31), is there still any chance that I could break into the equity research industry? What could I do to enhance my chance of getting more interviews? Would you suggest me to focus on sell side or buy side roles given my background?

Thanks in advance for your advice!