"Disable bone followers" should be off on all dynamic props anyway, as it adds overhead to the network. Not clear on what exactly is going on tech wise on bone followers (maybe something like each bone determines its rotation or position relative to its parent?).
Make sure you have a full default animation set. It kinda looks to me like the animation is being set to a gesture or damage flinch.
Or... or you could just run with it, and add an ambient_generic with a voice saying "Yes" and then play it constantly with a logic entity so it sounds like "Y-Y-Y-Y-Yes! Y-Y-Y-Y-Yes!"