Custom gravity causing jittery movement

https://dev.epicgames.com/community/learning/tutorials/w6l7/unreal-engine-custom-gravity-in-ue-5-4

I’m using the above custom gravity in my own player controller, but for some reason, the movement of the server-side player appears very jittery from the perspective of the client player. It looks like the server player is rapidly switching between falling and running animations, and I’m not sure why. Any ideas what could be causing this?