This has changed in the most recent Dev Branch update. When calling BIS_fnc_ambientAnimCombat on any infantry unit that is spawned above 0 elevation; the function does not work and the AI revert to their default state.
e.g. Previously I was able to post sentries on a roof using the "WATCH" animation - now they just stand their in an idle, aware state.
This is only affecting units above 0 elevation. Units spawned on the ground calling the function work as intended.