If you order a pillager on a ravager to attack buildings while in close proximity with targeted building, the range attack ai may glitch and keeps firing directly downwards on ground (or attacking the mount?) even after moved away from the said building. Usually result in quick death of rider. Tested on 1.0.6.

Update: Actually it's not just when attacking buildings. All mounted pillager AI is glitchy at the moment (1.0.6a) that they draw argo at each other upon friendly fire.

When I was playing, Ravager's movement became difficult to control when he encountered a building after being ridden

Mounted pillagers also use their mortar attack unprompted (as opposed to with an ability button), leading to some extreme silliness (and friendly fire).

Fixed in 1.0.7