Good morning,
I'm honestly not sure if this a platform-specific problem or if this happens regardless, but I'm on Xbox Series S and I've noticed if small Last Stand maps are overloaded with too many of those Chickens (especially water maps, i.e. Ice Breaker/Typhoon, because they float in the water and cause water splash animations), the framerate of the game becomes extremely choppy to an almost unplayable state.
Am I the only one experiencing this or have others noticed as well? It gets REALLY BAD with Typhoon especially.