Client's rotation jittery, but only in the host's game

Character’s head rotation is working except that in the host’s window the client still jitters. (Everything looks good when controlling the host, and when controlling the client everything looks good in the client’s window, but when controlling the client the client’s character jitters in the host’s window… just not in its own window)

My character is mech-like, uses the controller’s desired rotation and orients rotation to movement. I then get a rotation using a line trace from the player’s camera to modify/transform the upper body in the anim BP.

I Update the animation before the switch because the host wasn’t doing anything. The rotation I set in “Update Animation Variables” following a line trace, and is not replicated. The rotation is retrieved thread safe in the anim BP.

There you see I’m doing the same thing for several other rotations, but if I get the “head rotation” working properly the rest should work as well.

You are running update animation variables on the server execution. You need to run it on the local client and then send the results to the server.