And which PCIe slot is the card in ?
It is in slot 4 (mostly due to the cable reaching to that spot). I'm getting a longer cable on Tuesday so can move it wherever.
Thunderbolt 3 then you can plug into the USB header on your card to get usb2 support on the USB-C ports as well. I guess maybe you don't need Titan Ridge tb3 joevt does.
Got it!
For a test i would give the card External SATA power from outside the Mac Pro and see if it still ejects disks after going to sleep.
I don't have a way of doing this unfortunately. Let me see if I can come up with a solution.