Any third Party temp/voltage software installed: None
System Overclocked (provide details)?: Yes.
Memory at XMP timings.
Every few cold boots, I see the "(A7) ME Firmware Downgrade - Request MeSpiLock Failed" issue.
About 6 months ago I had updated my BIOS to 1301 from 906 (using default settings and updating the BIOS in order till latest) as well as some other ASUS drivers, all retrieved from the official ASUS support page for this motherboard, and that's when the issues started. Since then I've been getting different BSOD's in Windows and the Firmware Downgrade issue. The reason for the BIOS update was because 906 didn't have proper XMP support for my RAM.
I tried the solutions of swapping from Secure Boot to Legacy and back, clearing the CMOS, updating the MEI, reverting back to previous BIOS, checking the system drive and RAM for inconsistencies, but nothing has worked so far. The system will appear stable for some time and then start having issues again out of the blue.
I've reinstalled Windows 10 thinking it may be some issue with updating the BIOS and Windows 10 not liking it, but the same issues persist.