Objects use floating point values for their coordinates in Construct. Due to how floating point values work on processors the objects may appear to be at the same place, but their X and Y coordinates will differ ever so slightly. You would probably want to round the coordinates and just test to the nearest pixel. You would do it like this, using compare values:
round(Sprite.X) equal to round(Sprite2.X)
round(Sprite.Y) equal to round(Sprite2.Y)
If you want to test multiple 'Sprite's with this method, put a 'For each Sprite' condition at the top.