No, isn't a special, it is a Sequel and manga adaption. No fix needed. The episode in season 0 of that are remove.

Addition: https://www.crunchyroll.com/anime-news/2021/09/25-1/demon-slayer-kimetsu-no-yaiba-mugen-train-arc-and-demon-slayer-kimetsu-no-yaiba-entertainment-district-arc-are-coming-to-crunchyroll

help: https://www.themoviedb.org/u/banana_girl

ufotable / Aniplex seems to consider the Mugen Train TV Arc as actual regular episodes, even though they're just a recut of the movie, so I'd leave them in season 2. What I'm unsure about though is where to put the Entertainment District Arc, but I guess we'll know that on December 5th depending on if they end up numbering the episodes starting from one again.

Understanding

Sorry to recycle this thread.

Crunchroll and Aniplex both mark Entertainment District Arc as season 2. So we are shifted by 1 season for everything after it. Do we plan to correct that? Or should we use single season for all episodes?

@owlhuang said:

Sorry to recycle this thread.

Crunchroll and Aniplex both mark Entertainment District Arc as season 2. So we are shifted by 1 season for everything after it. Do we plan to correct that? Or should we use single season for all episodes?

Not fix needed. In one season we can't add two first episodes. We split it into arcs aka seasons.