"I have always thought of EXPO/XMP as "verified/approved" settings for memory, and not so much an overclock. Especially since the QVL reflects that. This is not the case, and in fact the rated settings also vary by CPU, so just because the QVL says 6000/30-38-38-96, does not mean that it should work across CPUs," wrote Speedrookie.
"With this in mind, as I state above, I purposely went back to a BIOS version which POSTed with EXPO which was not an approved version for X3D series CPUs and chalked this up to BIOS instability rather than a potential intention by the BIOS engineers. So for people on a similar build, I'd say just make sure to update your BIOS and forgo EXPO for the time being until we know things are stable and working as intended. The cause here is still speculative, however may be a good safety measure to take."