[12.0-U5.1] Kernel panic during startup pool import

[bal0an]

After a restart my main storage pool consisting of 5 SATA HDD drives failed to import with a kernel panic.
I have a second pool on the server consisting of a single SSD which works without issues.
The server ran for years without trouble. I've changed the CPU/mainboard to eliminate hardware issues, but the problem persists.
Any root cause speculation or recipe to make the pool to import again?

 

[bal0an]

I will try https://www.truenas.com/community/threads/zfs-has-failed-you.11951/ tonight after the memtest has completed.

 

[bal0an]

I was not successful recovering the pool. I've thus set up the pool from scratch and imported the backup overnight.
During recovery attempts ZFS claimed

Code:

cannot import 'tank': pool was previously in use from another system.
Last accessed by (hostid=208da16a) at Sun Oct 3 22:05:11 2021

The timestamp corresponds with the previous scheduled shutdown - but the pool was never moved between systems.

Loss of a storage pool due to kernel panic puts a huge dent in my trust with TrueNAS/ZFS.