I am running 18.104.22.168076. I recently reset my launcher to defaults (cleared all settings/data), then spent about an hour setting it back up again. After I was done I created a backup. Then I restored an older backup for comparison. When I tried restoring the most recent backup nothing changed. I had to set everything back up again.
I have replicated this again by creating a backup, then making some small changes (moving icons around), and then restoring the backup. The icons did not move back to their original positions.