I'm also having this issue with my 24TB G-Raid Shuttle thunderbolt 3. I can see the G-Raid in System Information, but not in Disk Utility, Terminal, or Finder. I also discovered that this issue is only affecting my Macs that have been updated to Monterey, which I confirmed by downgrading one to Big Sur. Once downgraded the G-Raid was visible again and worked as expected.
So I spoke at length this morning with Apple tech support about the issue. After going through the obligatory "have you tried powering the unit on and off" fixes with standard tech support, they referred me to whatever the next tier of support is called (advanced?).
Anyway after I described the issue to the advanced technician, he searched through what he called "some internal tech bulletins we use" and found one confirming this is indeed a known Monterey bug. He said it appears to be only affecting some G-technology drives that connect via USB-C or thunderbolt. Lastly he apologized and said that Apple's recommendation at this point in time is to downgrade to Big Sur until a patch for Monterey is released.