If the OS is unable to process the write operations due to a crash, it’s possible that the note that was actively worked on is corrupted (we are aware of this).
It’s possible, but less likely that File Recovery was wiped out, especially of all the notes. Let me state that we do not consider File Recovery a backup solution. You should have your own separate backup system in place.
I am even more surprised that a note that wasn’t even open got corrupted.
I am sorry for the data loss, but I really don’t know what happened to your system nor if Obsidian was responsible.