I have my Mac desktop configured to snap icons to a grid. However, for a while I’ve noticed that moving an icon causes them to snap to the upper-right corner of the screen, ignoring where I actually want them and overlapping existing icons. The only way around this seems to be going into Display Settings, changing any parameter such as Grid Size, and then moving the icons again. Has anyone else been experiencing this?
I had a similar problem while I was using macOS High Sierra (so that is a couple of years ago), albeit I was not using the snap-to-grid setting. After almost every reboot the operating system seems to have “forgotten” the icon arrangement. What helped was a third-party-app that remembered the icon positions. When the icons were displaced again after a reboot, you could restore their original position with one click.
Unfortunately I don’t remember the name of said app (It’s been a while, and later versions of macOs didn’t have this issue). It’s something along “keep icon positions” or “icon arrangement manager”.
I hope this helped.