I wondered if Aura Sync was causing some kind of conflict so I uninstalled it. RGB Fusion was now recognising both the RAM and the motherboard (to which the fan is connected) but the motherboard was greyed out and I couldn't interact with any of the controls.

Yesterday I noticed that my fan and pump were stuck on static green, and went into RGB Fusion to see if I could fix it. The fan and the RAM have never been in sync with each other but that's okay - I just set both to cycle through the spectrum and was happy with that. It stopped recognising the RAM completely so I downloaded ASUS Aura Sync to see if that would work as a solution for both (no) and then the G.Skill software to control the RAM independently. Now, RGB Fusion has never worked properly after about the first day. I downloaded RGB Fusion 2.0 to control that and the G.Skill RGB RAM. It has a Gigabyte X570 UD motherboard and a Cooler Master ML120L liquid cooling system, which has RGB LEDs in the pump and fan. Just after Christmas, I got a new PC custom built by PB Tech.

Rgb fusion cooler master