Does anyone know why my linetrace doesn't pitch up or down for the clients?
Will need some more info I think. If this is a function that is run on the server, then I’m pretty sure the rotation of the camera is only done on the client, so the server will not know the rotation of a client’s camera, and thus will only trace based on the default rotation of the component. You could maybe save the rotation of the camera on Tick and send it to the server, or have a parameter in the trace server function that you send the camera rotation when you call it from a client.
Also, a tip, you can multiply vectors with a float or double. In UE5 you can do that by right clicking the second pin of the multiply node and changing its type from the context menu