I didn’t see you were on a different instance - each community needs to be manually added to your instance’s federation list. Lemmy doesn’t federate the entire instance - just individual communities. You only see communities on dmv.social that have at least 1 subscriber local to your instance.

If you go to dmv.social in a web browser and you type https://kbin.social/m/wizardposting into the search bar on your instance, you’ll see it pop up in the search. Then you can subscribe to it on your instance and the community will start federating. You won’t see any past posts from before federation, but you’ll see future ones.