I’ve a 1019+ fitted with four 3TB WD30efrx in RAID 5, so I decided to expand my drive pool, I got a Seagate Ironwolf 4TB HDD, installed in spare bay, booted up, drive recognised, tried to add it, got error message, system failed to expand with Drive 5, tried secure erase, failed, am I being to ambitious trying to add a larger drive from another manufacturer, or could it be a dud drive ?