Thank you for your reply.
But currently I have exactly the problem.
When the client spawns an actor for itself and he tries to jump on it, for example, it seems for a short time that he is standing on it, but the server then notices that the client is in the air and puts the client back in front of the object on the ground. Since the server is boss, the client can spawn whatever it wants as long as the actor does not exist in the server, no collision exists.
So far I have understood it like this.
In my case the floor consists of these spawned blocks.
If a client spawns a floor it simply falls through. If the server has to spawn a floor for the client, the server would always have performance problems. So my question would be if there is a way for the client to spawn the floor without falling through and without the server having to spawn the floor for him?
Best regards
Sandro