photos will never be pngs unless someone intentionally converts them to that format, as pngs are much worse than jpgs for storing this type of image. pngs are much better for computer generated images, such as screenshots, drawings, etc. you can also losslessly compress pngs with tools like pngcrush without converting them to jpg.
it’s like @Xyre@lemmus.org described. old content does not get federated unless there is new activity on it and someone on your instance is subscribed to the community it happens in.
this isn’t anyone’s fault, it’s just a matter of the instance not being around that long that some historic content will be missing.
It should be noted that the (visibility of) community bans are a result of better enforcement of site bans in 0.19.4, which for now is implemented by sending out community bans for local communities when a user gets instance banned: https://github.com/LemmyNet/lemmy/pull/4464
Prior to this, when a user got instance banned from .ml, they were also implicitly banned from .ml communities, but this was only known to the instance they were banned on. As a result, users were still able to post, comment, and vote on those communities, but it would be visible only on that user’s instance, not federated anywhere else. Visibility of this ban was exclusively on the banning instance’s modlog.
I’m not familiar with n8n but it’s fairly straightforward on the API side.
You’ll need a session token, also known as JWT, which you can get from logging in.
You typically don’t want to do a login for every post, so you’ll want to store that as a persistent value.
For authentication, you can pass the header
authorization: Bearer {jwt}, with{jwt}being the session token.https://join-lemmy.org/api/classes/LemmyHttp.html contains the API documentation.
You’ll need to figure out the id of the community that you want to post to.
If you need to look it up, you can use getCommunity to fetch its details. Afterwards you can use createPost to submit it.
The
formlinks for the methods explain the request body json values that should be provided.