I did do the download and started a new game, playing on a Mac.
3 years ago (+1)
I'm not very familiar with Mac, but it sounds like Ren'Py may somehow be pulling from old save data even though you're starting a new game. I can only provide examples from a PC version, but Mac should be similar, just different file paths.
From what I can find online, you'll need to delete the save files in the game folder:
After you delete the saves from that folder, you'll want to find the When Stars Fall game directory in the RenPy folder since Ren'Py also creates it's own separate folder for saves from all the Ren'Py games you have.
From what I could find online for Mac it should be located in this generic area unless you saved it special when downloading:
game_directory is actually the name of the game you are looking for so:
Once you've deleted the saves from both locations, then you can start the game and it should all be reset, You should be able to get the new content. If it doesn't work, then I would repeat the steps above and uninstall/reinstall the game. If that still doesn't work then let me know and I can try reaching out to some other VN devs to see what insights they may have regarding the issue.