I had that happen after I bought TRS19 Platinum from the Trainz Store. My Steam version of TRS19 Standard acquired the Unified Driver Surveyor interface along with other Platinum features. When SP5 was rolled out on Steam as an update it lost all of those features and became TRS19 Standard Edition. I inquired as to why and was told that TRS19 Platinum was not available through Steam just the Standard Edition. It may be related to you having a subscription but I also had a Trainz Plus subscription at the time.
