Overwatch has a bug, it only works if the enemy voluntarily comes inside the area in their own turn, if you throw an enemy inside overwatch they will happily walk away when their turn comes without anyone reacting to it, situations where overwatch should but does not work:
Issue:
You break a door and right on the other side you have a group of enemies, if you leave your team on overwatch, then break the door, enemies will walk inside your overwatch area with no reaction, so your team will just stand there pointing at nowhere.
Expected:
You break the door and anyone inside your overwatch area gets shot if they move allowing for successful ambushes.
Issue:
You throw enemies inside your overwatch area using grenades or abilities, enemies will just walk out of it in their turn with no reaction.
Expected:
Enemies get shot when moving inside your overwatch area after being thrown in.
Issue:
You break a door and right on the other side you have a group of enemies, if you leave your team on overwatch, then break the door, enemies will walk inside your overwatch area with no reaction, so your team will just stand there pointing at nowhere.
Expected:
You break the door and anyone inside your overwatch area gets shot if they move allowing for successful ambushes.
Issue:
You throw enemies inside your overwatch area using grenades or abilities, enemies will just walk out of it in their turn with no reaction.
Expected:
Enemies get shot when moving inside your overwatch area after being thrown in.