You can’t sync variables from clients to the server, those are replicated Server->Client only, you have to RPC Client->Server and then replicate what the server receives to all other clients with a replicated property.
Also for the player movement components they send RPCs to the server with the recorded movements every tick or relevant change, it is how you do client authoritative replication in the engine.
Edit also shouldn’t need to set the relative location on the owning player… that should already be set by the motion controller itself.