Howdies. As requested:
1. Windows 10: 22H2 (19045.2364)
2. V4: 4.0.7.2
3. Somewhere around 112 icons consisting of 28 rows of 4 icons per row.
4. There's confidential data in the icon names, but I'll be more detailed. This has happened in all 3 desktop fences of the same size. Let's say I have 4 icons with the names: "z_Apple", "_Apple", "cApple", "Apple". That being the first row. Then, I have: "z_Blip", "_Blip", "cBlip", "Blip", as the second row, and so forth. Somewhere around the 28th row (let's say I am trying to move in "z_Monkey", "_Monkey", "cMonkey", "Monkey"), any of those icons, the moment they are moved in, will go somewhere random, for example, between "_Blip" and "cBlip". From then on, every new icon moved in will go right to that random point (right before the previous random location). Some time later, new icons moved in will find themselves in another completely random placement, with the same behavior. Any attempt to move them somewhere else will move them back to the same previously random placement. If there is any attempt to move them sometime later, they will find themselves at a new random location.