make sure you set up the patrol first. When the squad first spawns, it "generates" the patrol route. You cannot change it after that. You could even remove the patrol posts after they start patrolling, they just "remember" the waypoints.
It's very specific, the order that you have to do things. Just pick up the squad, stop spawning from the guard station, go and re-make all your patrol posts and connect with green wires. THEN try and spawn a squad from the guard station at one of of the patrol chain. You only need one guard station.