I have the exact same thing going on. Custom curves are not the issue, as the default fan curve ov "quiet" stays quite until after you run a game. Then from there on out regardless of temp (right now its at 50 c), both fans on the AIO are cranking at 2.5k rmp. The fans are connected to the AIO header directly, and nothing else should be controlling this. I specifcially went to the BIOS and also disabled control of the CPU fan there too.