I also have a set of DDR4-3000 corsair ram and a Z390-A Pro that is doing the exact same thing. In the bios the ram is set to 800mhz and I cannot change it or else I get the same msg, but I am able to run xmp with both single sticks in a single ram slot. Please let me know if you find some sort of fix for this.Hello.
I have msi MPG Z390 GAMING EDGE AC and G.SKILL TridentZ RGB Series 16GB 3000mhz. my ram frequency is 800mhz and when i want to overclock it or enable xmp it tells me this: