Do you have many communities blocked? All the Lemmy apps I use sometimes fail to load posts in the All feed, but I think it might have something to do with my account blocking thousands of communities.

In your case (especially if you're instead using Piefed), perhaps Blorp has a distinct glitch if its own, or there's an unrelated glitch common to them all, or something is problematic with the Lemmy API regarding mass-blocking. In any case, it's definitely something that should be fixed.