Thanks

the ‘trails’ only seem to work right if you follow it from the beginning or haven’t strayed off its invisible path.

when i know there’s a target in-mission, i just swap to the scanner. i usually melee anyway. quick melee and ‘zoom’ check every room. they will automatically swap. don’t even need to ‘look’ for the trail, the marker will pop-up and voiceover will start if you ‘check’ close enough to their spawn point (usually same or adjacent tile)