Is Spark remembering its position if you only move it in monitor 1? Spark is starting in the middle of the display if you move it’s window out of bounds of the display (case with 1 monitor only), so maybe it treats second monitor like “out of bounds of the first monitor”.
Btw, SPARK-881 says, that it remembers relative position. What happens if you move it to 2 monitor but not to the edge, but just in some corner. I think it will startup in the same corner, but on the 1 monitor. When you move it to the edge it’s very easy to move it by some pixels out of bounds and it will popup in the middle next time. Snapping to the edges of the screen and taskbar would be great to have indeed - SPARK-956