Your API is still broken.
Example:
gallery-dl https://mangadex.org/chapter/1199969/
[mangadex][error] HttpError: '404 Not Found' for 'https://api.mangadex.org/v2/chapter/1199969'
But the chapter works:
https://mangadex.org/chapter/1199969/
I guess I'll write my own scraper if the API is...