After today's update when I started TSW2020 it asked me to log into DTLive (it hasn't done before since the first time, and in my profile I've connected to my XBox Live account). Entering this info is quite tricky using a controller, but once I did it showed my my "Mastery" progress and it had all been reset! Is this a known side-effect of the update and is it lost for good, or just "missing" due to server issues?
Have you tried looking at your Mastery progress under your profile? https://live.dovetailgames.com/live/train-sim-world/profile My Mastery progress doesn't reflect in game & hasn't for some time. But, it keeps updated on the profile portal. Hope this helps.
Ah yes, it's all there. Many thanks. So when I complete the level I'll still get the background or whatever, even if the xbox isn't showing it properly ?
Yes, you should get it no problem. As long as any time the game asks you to sign in to Dovetail live, make sure you do. Otherwise it won't be able to track your progress. It's an issue that whatever mechanism Dovetail uses to track progress for the Mastery stuff, has always been pretty glitchy. I have had the same issues with their Fishing Sim games that uses the same system. As long as your game says you're logged in to Dovetail live, you're good to go!