When I want to use the original Train sim World everything works fine however when I load TSW2 up all but a random handful of routes are appearing, so I have to download all of my preserved collection routes again. P.S on the roadmap, it says that this problem is fixed.
I have uninstalled all dlc from 2020 that has been released for TSW2, that way I can play either game without any problems Not ideal as it means starting each game separately when I want to switch route