Thanks @Edhawk for the interest, response and detailed questions, I will try to answer:
1, 6, 7. Both were created in macOS the same way RAID 0 with Disk Utility App.
3. The 1TB Set that is working on the 0 and 1 Sata ports. The 6TB set that has this problem on the 2 and 3.
4. Not sure how...