Apple has reported that a nasty bug has been encountered while working with hard drives on the new Mac Pro.
SATA-connected hard drives are disabled due to a macOS boot error. This happens after turning on the computer after sleep.
This can automatically put it to sleep. If you see a message that your drive has not been ejected by a volume, you can restart your Mac to reattach to the drive.
– Apple
As a workaround, you can prevent your Mac Pro from automatically going to sleep. For this you need to open System Preferences -> Displays -> Advanced… and turn on the toggle Prevent auto-sleep when display is off.
Source: Iphones RU

I am a professional journalist and content creator with extensive experience writing for news websites. I currently work as an author at Gadget Onus, where I specialize in covering hot news topics. My written pieces have been published on some of the biggest media outlets around the world, including The Guardian and BBC News.