Cant reproduce it on custom simple map, so download blood stainhttps://www.doomworld.com/idgames/level ... ads/bstain
use this save (Gzdoom 4.4.2)https://drive.google.com/file/d/1zZkALa ... 5a6fv/view
Launch Gzdoom, load save. You should see twitching caco, which seems to stuck under the ledge. Fov increased for better observation.
Look like this happens because one of the vertex of it collision box collides with ledge bottom when it tries to move up.
Edit: Provided wrong wad first time, now I fixed error.