I've been having this issue lately where desktop icons would move one box upwards when logging in. It happens when I power on the PC, and when the screen is locked (both automatically and manually through Super+L). I couldn't find a viable solution, and it kept bugging me.
One of the "fixes" I saw consisted in disabling the default "Zorin Desktop Icons" extension through the GNOME Extension Manager, and installing the vanilla DING (or Neo), but I found them to be quite unstable.
Then I was fiddling around and accidentally discovered a "fix" for it, although I think it's more of a "trick".
I right clicked the taskbar and went to the Taskbar Settings -> Style -> Panel Intellihide, and I activated it. Then I moved the desktop icons (that kept moving) to the lowermost position (which is 1 block lower than when you have the panel on), and then I disabled the Panel Intellihide option. The icons automatically moved back 1 block up (to where they were initially), and that magically fixed the issue. I never had the icons move again.
Just to clarify, this only works if you want the icons to be on the lowermost position, because if they're not, then the problem will persist (I tested it).
Thanks for making a post about a possible remedy for a specific problem that seems to be a thorn in some peoples sides that decides to get worse some days than others. Hopefully, as you say, this can help someone with theirs.
If this works reliably, it may be the cause of this long standing bug. It may be worth looking into the order in which extensions run when the system starts.
What I think is happening is that when you hide the taskbar, a new line of "blocks" opens. When you place an icon into one of them, and then activate the taskbar, it's then impossible for the icons to remain in the position they were, thus they shift up one block to make way for the taskbar.
However, the system still registers the icons as being in the previous position, so when the bug happens, they still "shift up" a block, but on the desktop they remain in the same position.
In other words, I think the problem doesn't disappear with this "fix", it just gets masked because of how the extension works.
But then again, these are just speculations, and I have no idea how extensions work
By the way, now that you say it, I remember seeing something about a race condition related to this problem. And I just realized it was your comment
From what I understand, the icons themselves have an attached piece of metadata, coordinates that are used to calculate the position of the icon. The issue happens when something changes this coordinate system after this calculation, like screen resolution changing when accounting for another monitor, fractional scaling or other elements like the taskbar.
I don't know for sure, but that's what I think it's going on as far as I can tell.
