I searched "lock desktop icons" and got this article
auto arrange has absolutely nothing to do with it.
In windows 8.1...
five times a week I suddenly find my icons in a totally different pattern on the screen, a bunch on the right, others scattered. sometimes the whole group pops up on the extended screen like it just did.
they are not auto arranging, they're doing something else very different, verrrry annoying. I set them in groups for reasons and that valuable time goes out the window.
If I don't resort them again, I waste time trying to find them
.