On our raid cards, the array configurations are stored in array member drives. and once a member fail, the array status/signature in rest members will be modified. If the previous failed drive becomes normal after power cycle, this drive will report an identical raidset. But it does not belong to the original raidset because the array signature in this drive is different from others. Although these two raidsets have same raidset name but the raidset status/signature are different. You can check the raid card event log history to find out which HDD had been failed before.