Hidden units

[Mowgli]

Another strange situation I can't explain from my PBEM. I was recording it as a Let's Play in german, trying to explain some of the game's rules in the process. But then I don't seem to understand the rules myself. :)

Short version: I thought I was making a clever concealed movement with my infantry unit, carefully shielding it from enemy sight by deploying a smoke screen and blocking the enemy LOS with one of my stacks (with stacking above 50% of max. stacking limit). Everything looked safe on the "visibility overlay" - the target hex of the move was not visible to any known or potential enemy position. Turned out it did not go unnoticed. But I can't explain why. (My unit had orders to hold fire and never did anything suspicious after the movement).

https://youtu.be/g146CZPtdYM