Monitor says bank account details were leaked, how do I find out more?

Mozilla monitor informed me in multiple data leaks over the course of a few years that my information including sensitive bank details and accounts were leaked in a few breaches. That I need to alert my bank right away. I have the date of the breach but that doesn't tell me anything. I don't know how to figure out what bank to notify, or even how to begin narrowing down to look for suspicious transactions. Especially because suspicious transactions may not be so, and innocuous ones may be truly fraudulent. This may be my only opportunity to get behind the ball within the 30-day window banks require to notify them of fraudulent activity, and I need to know which bank. This is really stressful.