What is happening is icons are placed as if it were a single desktop not unique to that desktop. So if you have 3 icons top left on desktop 1, and each below eachother, then move to desktop 2 and download another file to desktop it will be placed at the 4th position available which would be correct for desktop 1 not desktop 2, which has no icons on it, so top left most location is available.
How to reproduce:
- Multi desktop enabled.
- Move to screen 1
- Open web browser download/save an image to desktop folder
- Move to screen 2
- Open web browser download/save another image to desktop folder
Might want to look into this, I do not want desktop auto sort icons on, that's the worst feature ever created and defeats the whole point of desktop configuration tools.