Very unstable system?!

I suggest updating BIOS before reinstalling system - Asus PRIME X470-PRO - BIOS & FIRMWARE

Really good suggestion. Last time I did it was something close to one year ago.

I’ve just finished cloning partition and I don’t really understand the output.
I’ve used clonezilla partclone with dd mode and -rescue flag:

Summary of image checking:
GPT 1st partition table file found!
GPT 2nd partition table file found!
GPT partition table file for this disk saved by gdisk was found: nvme1n1
This is not an image for whole disk. Skip checking swap partition info...
MBR file for this disk was found: nvme1n1
Image was saved by dd or partclone.dd. No need or no way to check the file system integrity: nvme1n1p2
The image of this partition is restorable: nvme1n1p2

PS. Next time you can run this command directly:
/usr/bin/ocs-sr -q1 -c -j2 -rescue -z1p -i 102400 -sfsck -senc -p choose saveparts 2022-11-11-12-img_MANJARO_FAILURE_BACKUP nvme1n1p2

I don’t really understand why there is MBR file, probably it is normal, but is it?

No it isn’t. Guess you didn’t recreate the gpt table. Windows like to have hybrid mod MBR+GPT:

In my experience mixing them is a bad idea on Linux.

So I have reinstalled the system, after updating the BIOS. This time I am using ext4 with disabled journaling. Overall fast write speed that f2fs offers would mostly be useful only when installing big updates (so not that useful)

For now I didn’t have any signs of unstable behavior. I will mark this as solution if after two months there will be no marks of instability.

From now I will do weekly system backups and I would recommend that to anyone.
When using such amazing tools as ventoy and clonezilla it is much less time consuming than trying to recreate all of data that could be lost,
take my word for it :)

And of course thanks to everyone here for time and afford!