I’m wondering if this is an issue with this instance, or a deliberate choice by either server operator which communities to federate between lemmy.ca and the other server?

In this case: https://lemmy.ca/c/[email protected] works, https://lemmy.ml/c/[email protected] works but https://lemmy.ca/c/[email protected] gives a 404 error code.

Any advice or available workarounds would be appreciated.> good 5-10 seconds for the result to show up. i believe it needs to query the server and takes a bit sometimes.

E: Answer thanks to smorks: You have to search for the community on lemmy-ui and wait 10 seconds or so for it to appear, then anytime after the community search result is essentially “cached” for everyone on your server and will appear immediately, even within a partial search.

E2: Search for !community_name@lemmy_instance.com in the searchbar, filtering by Communities. If it shows “No results”, try again in 10sec. If it shows nothing or the community then it is discovered and the federated URL (your_instance.com/c/community_name@lemmy_instance.com) should work.