I took advantage of the latest Winter sale to buy both the BR204 shunter and the Iselbahn -- Stralsund to Sassnitz route on which it operates. The route is a shunter's dream, but I've run the first two career scenarios without being awarded any points for completing them. I don't usually pay any attention to points, but it seems strange not to receive any at all. What's up? Nothing like answering one's own question: while writing this post, the solution suddenly struck me, so I opened TS, clicked the Settings tab and -- sure enough -- out of frustration with scoring I had removed its ✔. Excuse me while I give myself a dope slap!
That's easy! I got tired of losing points because I don't drive shunting activities at the speed limit, which is a built-in requirement in so many career activities on the newer TS routes.