This happened because you were using a RAID controller, usual solution is to rebuild one disk at a time on top, since the partitions are outside parity and will be recreated by Unraid, though since you didn't check that parity was valid after the new config you need to wait for the sync to finish first, when it's done, stop the array, unassign one of the data disks, start the array, if the emulated disk mounts and data looks correct rebuild on top, then repeat for the remaining disks.