What part of the code do I need to change?

I think it’s because JEANG never had another animation while Caspian started shifting.

Right here when he moves, it’s an “@” command and not and “&” command. One way to fix your problem would be to change it to an & command. Another way would be to add an animation to JEANG on that same line where CASPIAN starts idle_shiftweight_neutral_loop.