Okay so the disks aren’t also on UPS? That might actually be even worse than the whole thing getting turned off, ZFS is definitely not meant to be run on removable disks like that.

Okay so when you say “unplug the power” do you mean shut it down first or just pull the plug? The latter is a great way to corrupt your storage pools as ZFS uses memory for read and write cache etc by default. You definitely need to do a graceful shutdown especially if there is data that was recently written to disk, that’s why a UPS is so recommended. That said you can usually import an existing pool when that happens, I think there is a UI menu for it now.