I’m still learning the quirks of federation and the behaviors of communities hosted on different instances, so I apologize if this is something that’s been asked repeatedly.
I made a post to a community I am subscribed to at lemmy.ca, from my home instance at slrpnk.net. Public posts on that community (as well as the post that I made) are not showing up from my home instance. My profile page on my home instance does not show any record of the post that I made.
I was only able to find existence of the post that I made by going to lemmy.ca, and then finding the community that I posted to from there.
How long did you wait? Sometimes it takes some time for things to get federated.
As long as someone is subscribed to it from your home instance, it should get there, though.
Edit: A word