My start screen keep changing size, first im able to pin 3apps vertically, then suddenly 4. Then I change the order to make them fit, then it suddenly goes back to only allow 3 vertically again.
Yeah, sometimes this happens. Can't remember what makes it happen, but mine has done it before. I liked 4 tiles enough that I did a registry edit to give me 4 permanently. It makes my keyboard slightly, but for 4 rows of tiles I think it's worth it.