When is currently? I looked at the beginning of the syslog in the diags, disks 1, 8, 9, 10, 11, 12 and 13 were connected with USB, then they dropped:
Jan 15 13:01:40 JEJ-Unraid kernel: usb 2-4: Device not responding to setup address.
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Jan 15 13:01:41 JEJ-Unraid kernel: usb 2-4: device not accepting address 2, error -71
Jan 15 13:01:45 JEJ-Unraid kernel: usb usb2-port4: Cannot enable. Maybe the USB cable is bad?
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Jan 15 13:01:53 JEJ-Unraid kernel: usb 2-4: USB disconnect, device number 2
Then the disks errors:
Jan 15 13:01:53 JEJ-Unraid kernel: md: disk1 write error, sector=4294967280
Jan 15 13:01:53 JEJ-Unraid kernel: md: recovery thread: exit status: -4
Jan 15 13:01:53 JEJ-Unraid kernel: md: disk8 read error, sector=8633241376
Jan 15 13:01:53 JEJ-Unraid kernel: md: disk9 read error, sector=8633241376
Jan 15 13:01:53 JEJ-Unraid kernel: md: disk10 read error, sector=8633241376
Jan 15 13:01:53 JEJ-Unraid kernel: md: disk11 read error, sector=8633241376
Jan 15 13:01:53 JEJ-Unraid kernel: md: disk12 read error, sector=8633241376
Jan 15 13:01:53 JEJ-Unraid kernel: md: disk13 read error, sector=8633241376
Array did change after that, but that part is not covered in the diags due to log spam so we can't really see the problem, reboot and post new diags