The answer is that it absolutely has changed. It changed to the opposite side of what was promised by the Sino-British joint declaration.
Hong Kong is now essentially one country and one system, but the government, the Beijing regime, still calls it one country and two systems, making a false statement to make their political agenda still work, because they try to trick the international society.
Hong Kong was the same as 1997, but totally changed after last July. The national security law is overriding all common laws in Hong Kong—overriding—with no more validity for Hong Kong law to execute if the officials use the national security law. It is supranational.