I play on Nintendo Switch. On my ubisoft account when I go to my stats for 2021 everything says 0. 0 dance time etc. In game, unlockable items such as an Alias for "Dance to 40 main songs" says I've made 0 progress.
All the stat tracking seems to be working for my 2020 version of the game.
A related bug might be that after every song it ALWAYS says new high score even though it is not.
Link to screenshot from ubisoft page:
https://imgur.com/stMhIML
I wonder if it could be cause I originally played 2020, and then when I got 2021, something went funky with linking my ubisoft account