Replicated animation runs at half FPS

I am doing my first animation setup and trying to figure out how it all works.
No i hit a problem i can’t find the cause of. I have a simple attack animation, which playes when the variable RightHandAttack is true. So i set this variable to replicate, which works fine from server to client. Then to replicate it from the clients to the server i use an RPC via a custom blueprint event to set this variable to true on the server. Since the variable is replicated, it then replicates to all the clients.
This works, but the animation plays very “laggy” on the server and the other clients, about half the FPS. I don’t do anything fence, i just check for the variable to be true. The movement animations, which are automatically replicated are just fine and smooth.

Anyone got an idea what could be the cause of this problem?

Seems to be just a weird performance issue. It’s not happening if the server runs on a different machine.
I don’t understand why it’s only happening to this animation but i take it as a weird quirk.