Oh this is interesting, it turns out the issue is more to do with how I am determining if a player should be in their ‘Idle’ state that is causing the crash
(Which isn’t being calculated if they’re already in the Idle state, which made it seem like changing to ‘CS_Moving’ was causing the crash, when really it wasn’t at all!
Thank you for your help, AnXgotta, I now have a new problem to tackle haha.