Often on this forum the question pops up: “Who should I open a live account with”
Along with your own due diligence, the following website is useful. Enter the brokers name (it’s trading name, this can typically be found at the bottom of the brokers website in the small print)
Pay attention to the tab on the attached link named “Disciplinary and regulatory action”. Here you will see all fines charged to a broker or ongoing investigations due to unfair conduct.