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.

Sadly, in this world you accomplish nothing for being nice and considerate. If you want to leave an impact (anything - a new invention, a new product, a new idea, anything with impact to contemporary culture) you have to bully yourself to the top, including stealing ideas and screwing people over, as well as to exploit people. All “great” people who accomplished something did that: Gates (Microsoft), Jobs (Apple), Musk (Tesla, Twitter), Bezos (Amazon), Thiel (PayPal, Palantir), Zuckerberg (Meta), Huffman (Reddit), as well as many politicans. It’s a personality treat.

Here is a video that explains the issue, albeit it focuses on designers: