WD EX4100 not accessible after RAID rebuild / resize

Hello,
Am trying to find someone that help me troubleshoot the issue am facing.

I initially bought my EX4100 with 4x10TB of Storage, on RAID 5, which gave me roughly 28 TB of data.
Recently (last 6 month) I reached 2 TB of free storage, so I felt the need to upgrade and expand my storage.
I ordered 4 x 22TB WD221KFGX HDDs and I started replacing 1 by 1, foreach disk to do a RAID rebuild and ensure that the data is consistent, then waited a couple of days and replaced the other one, it took me a couple of weeks to finish all of this.
After the last HDD was replaced and RAID was rebuilt, I had to expand my RAID5, so I went on GUI and started expanding, it took couple of days to reach 80%, then my issue started to happen.

The EX started to become unresponsive and lose network and connectivity, I rebooted it, once rebooted it gains the network, then I can access the GUI and SSH but after 5 min, it just go into veggie state again.
I kept trying to find a solution in those 5 min when the SSH is available, I found that my drives are unmounted and storage tab started dissapearing from GUI, then after the 6th of 7th restart, the GUI is stuck on performing consistency check and I cannot access the SSH anymore.

I tried to do a 40 second reset to try to reach it again but with no hope.

Can anyone point me in any direction that I can troubleshoot the issue, but I am trying as much as I can to retain the data, last time I checked it was there, its about 25TB of history.

Thanks for the reading and any support you can provide.

Hi @maraouf
Have you opened a Support Case? If not opened, for more information, please contact the WD Technical Support team for the best assistance and troubleshooting:

Unfortunately, WD support are replying with canned responses toward taking my device to a data recovery center specialized in retrieving data from malfunctioning drives which is not my case.

Thus am seeking the help of the community, maybe someone is more experienced than the support.