Rudder not working after starting cold and dark

Hi, I kinda need some help because when I start a flight cold and dark, after I start everything up and all the engines, my rudder doesn’t work and I can’t taxi properly because I can’t turn. But when I select ready for taxi instead of cold and dark, the rudder works… Am I not pressing a button or not switching something on properly on startup? I wouldn’t be surprised because I am very new to flight sims. If anyone could tell me what’s wrong that would be much appreciated!