When it is circulated with the SIFA system activated and the Service is saved to continue it afterwards, nothing more restart this Service the emergency brakes are activated (SIFA suppression). To avoid this, I must confirm the SIFA during the load screens of the Service, since not doing so the SIFA will activate the emergency brake as soon as the first screen appears with the train circulating.
Hello Juan Manuel Luengo ! The problem with loading an RSN service is that you, from the perspective of the game, don't get loaded into the cab - i.e. the player is loaded too late. The SiFa system will apply EMG-brakes five seconds after the driver leaving the seat. To prevent this, you need to stand up and sit back down at the driver's seat when the service loads. That way the game will know that you're sitting and SiFa won't get activated in 5 seconds. If you acknowledge whilst the scenario is loading, the player will also get loaded into the seated position. This is also why you may never get out of the cab whilst driving and SiFa is on. Hope I helped, Prof.