If the actor pre-exists in the level then physics replication will always be a catchup jittery mess.
You need to spawn the actor on the server. To test, spawn it via the level blueprint.
The cons to physics actor replication is it is not deterministic at this point. Meaning you can and will get different behaviors at times. Depends on server tick rate, replication update rate, client ping. Also they’ll never truly be in sync. The server is always n milliseconds ahead of the client in regards to it’s owned actors.
Another option outside of physics movement is the projectile movement component.
