Issues with Toshiba N300 4TB on T6-423

[realdvk]

TLDR:
TOSHIBA HDWQ140 (N300 4TB) drives are not recognized at startup in bays 4 and 5, but recognized on startup in other bays (1,2,3,6). Seems like harware bug.
Full story:
Recently i brought new T6-423 NAS. The initial setup was simple:
1x m.2 nvme samsung 1TB as single disk
3x sata toshiba n300 4TB as RAID1 storage pool at bays 4,5,6
I copied some data on them and the setup worked perfectly. Some reboots was applied and worked perfectrly.
After that i added:
12TB toshiba n300 as single disk at bay 1.
another sata toshiba n300 4TB as single disk at bay 2.
I copied some data on them and the setup worked perfectly. Some reboots was applied and worked perfectrly.
After that i added:
250GB samsung SATA SSD at bay 3 without storage pool creation. and shutdown the system.
Issues begins there. After boot the drives at bays 4 and 5 was not recognized by kernel and RAID 1 was degraded. In logs at /var/log/messages i found that kernel thinks that bays 4 and 5 are empty on boot. Other drives was successfully recognized. I have done some investigations and found that drives from bays 4 and 5 are in good condition and working perfectly in other PC. So I removed SSD drive from bay 3 and plug faulty drive to bay 3 and reboot the NAS. Drive was recognized perfetly on boot and RAID1 rebuild was initiated automaticaly.
After that i have tryed diffirent compositions and found that all of my TOSHIBA HDWQ140 N300 4TB (i have 4 drives of this capacity) are not recognized on boot at bays 4 and 5, but sucessfully recognized at other bays. I note that my TOSHIBA N300 12TB is sucessfully recognized at any bay.

[TMzethar]

This seems to be affected by your SATA SSD.What was it used for before?
If you encounter this situation again, please generate and download the log report in TOS > Technical Support > Report Issues, and then send it to our support team mailbox or customer service window of the official website homepage as a network disk sharing link for analysis.

[realdvk]

That normal SSD was used in other PC sometime. And after that, was used by SATA-USB adapter (Orico) to transfer data from QNAP to TMNAS.
I found that there are only BAY 1 and 2 SATA ports are visible to BIOS. So I conclude that your NAS use separate SATA controller(s) for ports 3-6. I think this controller is not good enougth. I have looked at logs and found that the kernel think thouse bays are empty. I don't see any point in sending logs. This is definitely a hardware problem.

[TMwuu]

{L_BUTTON_AT}realdvk

Hello, T6-423 product HDD1/HDD2 are SATA signals directly from the CPU, and HDD3/4/5/6 are transferred through a PCIE to SATA chip.
Can you help with 3 experiments?
1. Only these hard drives (3x sata toshiba n300 4TB as RAID1 storage pool at bays 4,5,6) are installed in the T6-423 device. Can they be recognized normally?
2. Install the original n300 4TB as single disk at bay 2 and install it to the HDD4/5 position of T6-423. Can it be recognized?
3. Take out the 250GB samsung SATA SSD and keep all other hard drives unchanged to see if they can be recognized normally?