I thought beehaw.org defederating from us would not affect post/comments on shared source instances, e. g. lemmy.wtf, which is neither defederated from beehaw.org nor us:

https://lemmy.world/post/149743

Why do I see posts/comments from beehaw users on communities outside lemmy.world and beehaw.org?

That's because the "true" version of those posts is outside beehaw. So we get updates from those posts. And lemmy.world didn't defederate beehaw, so posts/comments from beehaw users can still come to versions hosted on lemmy.world.

https://codeberg.org/fediverse/fep/src/branch/main/fep/1b12/fep-1b12.md#the-announce-activity

After the group successfully verifies and wraps the received activity, it sends it to the inboxes of its followers. Followers then use the outer Announce activity to verify that the content was really approved by the group. After this step the Announce can be discarded and only the inner activity shown to users.

Cloudflare Challenge?

Since lemmy.world is now behind Cloudflare, is it possible that federation is hit by Cloudflare Challenges as described here?