In fact, if I launch 2 instances of the server (with different ports) in batchmode, In the windows task manager, only the first instance is using CPU (about 50% due to dual core), the other one takes 0%.
When I launch theses 2 instances without batchmode (so with rendering process), in the task manager, one instance is using CPU at about 30% and the other at 20%.
The result in batchmode is that the client cannot switch from 1 instance to another because the second instance cannot process client connection.
Thanks to you! I could solve the problem.
It was the Camera Gameobject that was enabled in server build and then was eating all the CPU. When I disabled it, everything worked.
I’m still curious why the camera component give this behaviour in batchmode. Thought it was skipped.