Migration not recoginizing volumes from 6404T to 6604T

[dandymanz]

I am trying to migrate my HDD from my old 6404T to a new 6604T unit.
As i understand from the NAS 343 resource, i just need to plug out the HDD from my old NAS into the new one for things to work.
On my 6404T, i have a single 4TB HDD as volume 1, and 3x 14TB Raid5 as volume 3. Both volumes have been formatted as EXT4. Firmware on 3.5.2.

When i moved all HDD in the same sequence to the 6604T and bootup, the NAS asks me to initialize the unit and says it will wipe the volume and all information.
When i try it from a web interface, i see that all 4 disks shows as single disks, and even the raid5 information isn't present.

Can anyone guide me if i did a wrong step? Or were there changes in ADM 3.5 that won't allow migration.

[orion]

Did you move disks when the old NAS and the new NAS are in power-off state? I did the process before without any issues (different model). If the problem remains, I think you should send a support request to asustor directly. https://support.asustor.com/

[dandymanz]

Yes. I did move the disks only while both NAS were turned off.
I was able to do it in the past with different models too.
Will file a support request with Asustor direct then. Hope this can be resolved.
Thanks.