I did reset my Edge 1030 last week, reverted to old firmware. The Edge now says "Training load is based on last 7 days of activity". So maybe things will get updated in a few days...?
Is was due to a reset of my Edge1030. By that, I lost history which Training Load apparently is based on. Coming back "online" with some data, TL startet again yesterday - after 7 days of data in the history.