First of all, check that your spaceship is using physics... Go to your pawn blueprint, and look at your static mesh
Check simulate physics, put linear and angular damping at 1, to have enough frictions, to slow your ship in rotation or movement (otherwise it will speed very highly, and rotate very quickly... :p)
It is a space game, I disabled gravity.
Physics is important on server, but totally unusefull on client, so desactivate it, on begin play event.
As you see you choose remote on switch autority, to disable physics simulation only on client side.
I am using physics because, I wish to have bounce behavior, collision, and so on. So I will add Force to my mesh, to make it move forward.
I will do this on server
And this is it, your pawn is moving. But client didn't see the move...
I created a custom event, I will use to broadcast the new position/rotation to client. I give to it, vector and rotator as parameter.
Multicast == broadcasting
On server side, I will get my rotation, and location, and give it to my custom event. Custom event will run on client side, I set to my mesh, the new position and location.
Global schema is this
