The Toshiba 12TB hard disk was disappearing when waking from standby properly. It was connected to the MSI X570-A PRO SATA ports. Even servers support standby to reduce operating costs and use wake on LAN to activate when needed, The Toshiba disk has been a great asset in the machine with its excellent capacity and excellent workload capacity.
Hopefully the move the Marvell 92xx SATA controller will resolve the issue as that disk is home to a large number of games. Last year several disks were procured to boost the overall studio storage capacity. Additional disks are planned but pricing is elevated due to chia mining which has caused a supply disruption.
It still is a mystery why the disk disappears from the machine when waking. Ordinarily all the disks are present. Rebooting the machine restores all of the disks but standby seems to cause the disk to disappear until the machine is rebooted. The older Marvell 91xx SATA card does not seem to be stable with Windows 10 for some reason. The 91xx has a SATA port expander to support 8 ports.
While the machine was disassembled the front USB boxes were secured with a screw. The Corsair Obsidian 750D has a tool less design which means at best one screw. The concern is the mechanical strain on the single screw may become excessive and cause shearing forces adequate to cause failure. General friction however should be able to secure the front panel boxes without concern for the screws to shear.
The 750D also has 9 disk bays installed as the front panel is not being used for a water cooler assembly. There is adequate room for video cards however the recent RX 6000 cards are 12.2 inches due to the 3 fan assembly.
I also removed the last remaining Seagate 4TB disk for the SPEC-01 rig which is running iTunes as a media center. The machine has a small SSD for Windows and iTunes and the disks handle media. The MSI X470 Gaming Plus with the R5 2400G is overkill for a media host. The MSI B350M Bazooka currently has the Athlon 3000G processor.