The Ryzen 1800X cannot apply an XMP profile.
The Ryzen 1800X cannot apply an XMP profile.
It seems you're experiencing difficulties with something that's hard to understand. Keep trying, but if it gets worse, let me know.
Today's update from F3b to F3 on Gigabyte GA-AX370-GAMING K7 was shared. I successfully configured XMP at 2400Mhz without issues. Setting it to 2666Mhz needed more than 3.9Ghz on the CPU, which I did (otherwise the PC wouldn't boot). After applying 1.4V on the CPU, I managed to boot with 2667Mhz on memory, though the PC remained unstable.