Posts and pictures may not upload correctly, or at all, or maybe magically appear after seeming to not upload. Comments may also duplicate. We will tidy house once we get some stability back after the recent update to 0.18.1 and increased user load. Thank you for trying to continue to upload images for the community.
What lemmy devs need to do is to allow database sharding. Instead of 1 postgres, allow specifying an arbitrary number and shard by community or, maybe, even post ID.
We may also have a nefarious instance user attempting screw things up according to here: https://lemmy.world/post/943832