If your server is using an NVMe disk, the top header in WHM >> System Health >> Show Current Disk Usage may appear white and be missing information, instead of the typical gray color you see on other pages.
This issue is due to the system not properly gathering data from servers with NVMe disks.
We've opened an internal case for our development team to investigate this further. For reference, the case number is CPANEL-41715. Follow this article to receive an email notification when a solution is published in the product.
There is no workaround available at this time.