I have seen similar things to that on High Sierra on a APFS filesystem. ended up re-formating the drive and reloading the O/S. Not Saying that is the right course of action. my client wasnt patient enough to find a solution. after a few days of talking to support and google’ng stuff and nothing working for them, I had to go the destructive route.
98% of my filesystem related errors/issues on Macs is all around APFS. HFS+ volumes dont appear to have issues (like APFS). now my sample size is small (30-40 machines vs apple’s millions) so dont take this as the gospel. This is just what I have seen.
Yet another reason to only use 10.14 on test systems …
We also see a number of low-level filesystem issues with APFS when backing them up. Even though a few of the HFS+ stat properties have been removed from the API, Apple returns default values instead of a normally expected error when accessing them. This causes issues if you support the full bsdflags set.
[quote=432291:@Carlo Rubini]Thank you all for your advices: appreciated.
My fear was the SSD was going to die.[/quote]
do a quick check with DriveDX : https://binaryfruit.com/drivedx
it will tell you if your drive is dying or not.
and the demo runs for free for a week or 2.