I'm glad you asked! First, some resources:

- Community Browser: https://lemmyverse.net/communities

- Anime Community Compilation: https://sopuli.xyz/post/779648

In my experience, these have been the most reliable for seasonal anime episode discussions:

- https://lemmy.ml/c/anime

- https://lemmy.world/c/anime

I haven't browsed the manga communities as much, but so far these have been good for chapter discussions:

- https://lemmy.ml/c/manga

- https://feddit.de/c/manga