Either the problems with its API responses are breaking lemmy.world, or a broken lemmy.world is causing problematic API responses.
Currently, you can ask lemmy.world for page number billion of its communities and it'll return a response (for the communities it thinks it has on that page, rather than an empty one, as it should). For something like lemmyverse.net, this means its crawler can never get to end of a scan, and some apps are maybe trying to endlessly load the list.
References:
https://github.com/tgxn/lemmy-explorer/issues/139
https://lemmy.world/post/2651283