Nothing4You
Except it wasn’t created on lemmy.ml, it was created on lemmy.world.
lemmy.world then informed lemmy.ml that it is intended to be published in the community that it was created for.
It doesn’t say “crossposted from lemmy.world” but “crossposted from canonical_post_url”. This is not wrong in any way, although it might be a bit confusing and could likely be improved by including a reference to the community. The instance domain should for the most part just be a technical detail there.
It should also be noted that this format of crossposting is an implementation detail of Lemmy-UI and other clients may handle it differently (if they’re implementing crossposting in the first place).
I’m not saying it’s technically impossible, although it would likely be a bit challenging to integrate on the technical level, as the community instance has no authority to modify the post itself other than removing it from the community at this point.
The existing fedilink is already present for technical reasons anyway, so this is currently only showing existing data.
Why would you want a lemmy.ml link though? On Lemmy you’re typically intending to stay on your own instance, which many third party apps already implement. For Lemmy UI there is already a feature request to implement this, although it might still take some time to get done. If you have the canonical link to an object (which will always point to the users instance) Lemmy can look up which post/comment you’re referring to in its db without any network calls when it already knows about the entry. If you were linking to the lemmy.ml version of that post then the instance would first have to do a network request to resolve that and then it would realize it’s actually the lemmy.world version that it may or may not know about already.
it doesn’t matter whether you consider it reasonable, as it’s this way for technical reasons.
when a post or comment are created they are created on the users instance. the users instance then tells the community instance about the new post/comment and the community instance relays (announces) this to other instances that have community subscribers.
the fedilink is an id and reference to the original item. this unique id is known to all servers that know about this comment and it is what is used when updates to the post are distributed. except for the reference to the item on the originating instance, no instance stores information about where to find a specific post/comment on a random other instance.
The “fediverse link” on a post always points to the instance of the person who posted it, not the community instance. When posting from a lemmy.world account this means the fedilink is always the lemmy.world post link.
It is only shown for content coming from remote instances in Lemmy UI 0.19.3, although a later version changed that to always show.
What do you mean by “finish federation”?
Generally, individual activities (subscriptions, posts, comments, votes, etc) are federated within less than a minute of them being created. Your instance learns about other instances e.g. from votes seen on other instances. You’ll need to start subscribing to some communities on other instances to get started. You may want to check out Lemmy Explorer or Lemmy Community Browser to find communities and Lemmy Federate to automatically subscribe to other communities and get content sent to you.
The allowed instances list means that the instance will only connect to those instances and will refuse to send activities to any other instance.
this is by design. actor ids (unique identifier for accounts) should not be reused due to undefined behavior for how other instances will deal with that.
if you want to have a more technical explanation, https://socialhub.activitypub.rocks/t/reuse-of-identity-channel-addresses-revocation-reissue-of-keys/2888 does a decent job at explaining some of the issues with this.
it should be noted that these bans are community bans, not instance bans. your title makes it look like people are getting instance banned from lemmy.world, while the examples you’ve shown are about community bans.
if i’m not mistaken, several/most of the lemmy.ml bans/ban complaints have been about instance bans, which affect all communities on the instance.
the main problem is still that reports are not reliably getting to remote moderators: https://github.com/LemmyNet/lemmy/issues/4744
other than that it should be working.