Failed HDD rebuild problems / array errors brand new IronWolf disks

[cpu]

I had HDD failure and my current setup of HDDs is as follows:

8 TB parity disk

4 TB xfs_encrypted <- this one failed

4 TB xfs_encrypted <- this one is good and running

Once I found out that 4 TB died I replaced it with 8 TB brand new disk, assigned to replace missing disk and started rebuilding array. 

Parity is valid/rebuild is completed -> Finding 0 errors Duration: 13 hours, 10 minutes, 25 seconds. Average speed: 168.7 MB/sec

But after reboot I cannot mount disk due to -> Unmountable: Volume not encrypted

I started array in maintenance mode and so far with -nv options I have:

Phase 1 - find and verify superblock... bad primary superblock - bad magic number !!!

So now I need to wait to see if this is recoverable and then I'll have to try xfs_repair - am I right? Any extra steps to follow?

Edited September 29, 2021 by cpu

[cpu]

And this is my diagnostics file

sigma-diagnostics-20210928-2302.zip

[cpu]

Well a new problem just appeared - parity (month old IronWolf) and brand new replacement have errors - pretty rare situation to be honest but well that's my dagnostics.

sigma-diagnostics-20210929-0815.zip