I played the Train Sim World 2020 intro a couple of times the Great Western railroad class 166 that I drive always gets stuck at the red Signal a few miles after leaving Twyford.
Not sure if it's the same one, but there's at least one service on GWE where the manual points out of the depot aren't correctly set for you. Before you start off, zoom in on the map and check your route out of the depot, making sure all of the points are set to keep you on the blue path, otherwise you'll find yourself at a red.