Same issue, and I have the evidence! 4O21 runs south and is brought down to red, as Aroused by Trains suggests, by a 4-Car 350 (1L71) just hanging out on the line shortly after a signal - not even being held at red at a signal. It appears to have encountered a fault (if your imagination can stretch that far) and will need deleting to continue. Sleuthing further, I then ran the 350 service 1L71 from Crewe to Birmingham and didn’t encounter a single issue - in fact, I’d say that run was an ‘Awesome Service Mode’ run.. passing under a flying XC at Norton Bridge Jct., racing into Stafford with a Pendo, pushing a WMR 170 along the adjacent platform arriving into Wolverhampton and meeting another Pendo at the exit of the tunnel into New Street!
