Experience Aliens: Colonial Marines how it should have been when it first released. This mod includes fixes to AI, textures, balancing and more.
Finally the Xenomorph AI is what I would call 'fixed'!
A function called 'Displace' is the primary culprit that causes the Xeno's to just stop in there tracks, sometimes for a moment, sometimes indefinitely.
Unfortunately I can't fix the function itself, however I can stop them from using it. This is the result