Well the difference related to the nvme drive and dmesg I found:
[ 3.396539] nvme nvme0: missing or invalid SUBNQN field.
[ 3.405780] nvme nvme0: allocated 64 MiB host memory buffer.
[ 3.436120] nvme nvme0: 15/0/0 default/read/poll queues
[ 3.443329] nvme nvme0...
I read somewhere that HP EX 900 SSD had issues with the controller of the SSD drive, but in older kernels, and in theoretically it is fixed...
With other (previous) kernel it just boots fine for me (but maybe finaly it will be only inside the 5.5?). Do not find the link again.
I just upgraded the system (and kernel got updated too) to pve-kernel-5.4.55-1-pve
But it does not find root zfs anymore. If boot to previous kernel it works. I even tried reinstall, and afther upgrade the same problem.
If i try to manually import, no pool found.