Always best to start a new one, but since we're here, the problem was the controller:
Feb 11 06:55:01 Babs kernel: ahci 0000:01:00.0: AHCI controller unavailable!
All connected disks become unavailable, Unraid disables the first one to error on write (with single parity), the other will have read errors.
That is a Marvell controller, and we don't recommend those, though not necessarily related to the current issue, try re-seating the controller, power back on and post new diags, note that the disable disk will remain disable.