In the ESXi logs (/var/run/log/vmkernel.log or /var/run/log/vmkwarning.log) you see the warning message:
 
“The platform has enabled CPU cache Flush to NVDIMM Durability on Power Loss, but ESXi does not support it. As a result, write persistency loss could occur in the event of a power loss. Please disable this feature in your platform BIOS."

Some platform that contain Persistent Memory (PMEM), such as Intel Optane™ PMEM,  may enable CPU cache Flush to NVDIMM Durability on Power Loss. However, ESXi does not support it. As a result, write persistency loss could occur in the event of a power loss.

To resolve the issue, please disable CPU cache Flush to NVDIMM Durability on Power Loss in your platform BIOS.