I can only find one module, Baldur's Gate: Descent into Avernus, for a season 9 module for AL. Are there any other season 9 modules?
Baldur's Gate: Descent into Avernus is not a module as DDAL defines them, it is a "hardcover adventure". The individual modules are available on the DM's Guild.
You'll want to consult the DDAL Player's & DM's Pack, particularly the Player's and DM's guides with in it to see what the distinction between hardcover adventures and modules is.
That bundle also includes the content catalog, a listing of the available modules and hardcover adventures.