I have earned 102 gold medals but i did not get the trophy for 100 gold ones I have earned most of them in the Hauptstrecke Rhein-Ruhr dlc package because i'm working on completing that dlc
Gold medals earned in training don’t seem to count. It will pop. Mine did at something like 115 medals.
Another thing, if during the scenario or timetable service I've loaded the game, I ended up with points, but without any medal. The in-game profile counts this medal in such cases, Steam did not. And then, one day, my profile and Steam were reset [PC]