Alfiere i think this is supposed to represent a message, so technically just because your scouts have spotted the enemy does not mean to say you will see it on the F2 map.
You may see question marks with the last time they were seen. They are only observations, in all honesty if your scout is that far ahead, realistically he and probably a great deal of your own troops should not be displayed, it is all because we have friendly visibility set to unlimited i think it is??
I like it like this because it is great to have the fog of war represented this way, in many games i have not attacked an area with multiple enemy units displaying a ? because i am not sure if they are really there, and then when i see the replay from the enemies view point i am mostly surprised to see hardly anything there.
Hope this helps.