"Spot enemies at objectives using Recon gadgets"

Yeah, I'm so confused on how the spotting is even supposed to work. Like am I supposed to hit a button to spot the enemy targets or is it doing it automatically? I think its automatic, but it only gives me points sometimes when I spot the enemy. It also only counts for the specialist challenge sometimes. I cannot seem to figure out why the challenge counts some of my spots and not all of them even when they are CLEARLY on an enemy site and they are all marked on my drones HUD.