Can you provide some more information?
What motherboard specifically?
Have you connected the Ryujin through the USB port on the motherboard?
Can you be more specific about the issue? Are the settings just not holding? What about pump and rad fan speeds?
It must be something specific to your set up. I just finished a re-build with a 9900k, Maximum XI and Ryujin 360. Works like a champ.
Did you use the latest Armory Crate from the support site and update the drivers and device apps in Armory Crate?
I have a similar issue. On about 50% of restarts my OLED settings get reset.
Worse now I can't even install Armoury Crate anymore so I can't adjust the fanspeeds or OLED screen at all. The micro vrm fan steady blows very loudly now. I am considering removing and replacing the aio as it is consistently loud under no load to be unusable. For a "premium" cooler this has been an awful experience this past 8 months.
Consistently hoping for some update to fix with Asus and only having the quality of the software DEGRADE over time.