Water housing outlet replaced but leaking still

Hello, my car overheated and leaked out coolant. I took it to be repaired they replaced the water housing and thermostat and it seemed fine for about a month when it again overheated and leaked a ton of coolant. My mechanic replaced the water housing again with a dealer part rather than a cheaper version. But it still seems to be leaking. I have a video showing what’s happening. Not sure if I can attached it. Now he is saying it is probably the timing chain? Any idea why it would still be leaking after replacing the water housing? I attached the video to show how it continues to leak large amounts of coolant.