During a Chaos invasion, Warriors of Chaos armies that won a big battle often just stay at their place afterwards, not doing anything at all. Not moving, not recruiting, not changing stances. They just don't do anything. I've seen this during several playthroughs, but thought i'd finally report it since it's still in the game and just looks silly.
The following army razed Hell Pit and killed Throth's army inside it. It has been standing here for way over 20 turns:
The following army (bottom of the two on the screenshot) lost to a Grimgors' Ardboyz army, ran away and has since not moved. The top army of the two eventually spawned later on, moved there, destroyed Khazid Irkulaz and the bottom army is still standing there.
The army near Niedling won from a Vampire Counts army but has since stood there, not moving at all for at least 15 turns. The army near Gryphon Wood won from Drycha's garrison and razed it, but has since not moved at all, for at least 20 turns.
There are many armies on the map, and only the armies with still a large number of units in them are actually moving (some won battles, some have only run after spawning). Armies that lost at least half of their units just stand there on the spot they last fought, doing absolutely nothing.
I'm playing on Mortal Empires as Taurox, but have seen it happen as other factions too. I've set the Chaos Invasion to legendary, but i'm 99% this also happens on other settings (and is not related to that). No mods, newest version of the game. I own all three games and all dlc's for WH1 and WH2.