Hi, A problem has been occurring with a lot of people on X870 motherboards when enabling Expo.
Fix:
1- Clear CMOS by removing the power cable and then either press clear cmos button for 1 second or remove the battery for 5 minutes and then plug in the power cord again the system will boot again without expo.
1- You need to flash your motherboard with the new beta bios: https://rog-forum.asus.com/t5/amd-600-series/x670-resource/m-p/1055351/highlight/true#M7740 (don't forget to rename the file according to your specific motherboard based on previous bios names. for example (strix x870e-e rename it to A5557.CAP)
2- Move the NVMEs from the top gen5 slots to the bottom gen 4 slots in your motherboard avoid all the NVME slots sharing pcie lanes.
3- Enable Expo 1 and when the system restart go afk for at least 10 minutes and the system will reboot again with expo enabled and full ram speed.
Unfortunately if you have gen5 nvme you'll need to settle for gen4 speed until the official fix comes out. if you already have gen4 nvme you're not effected.
Its a fix for now, but definitely need to be addressed and fixed asap by Asus.
