Lemmy Support

Hey all, just wondering if I'm missing something or just have a fundamental misunderstanding of how federation works. I spun up a small docker instance for myself in order to interact with federated lemmy without bogging down the existing servers. I am noticing that although I am subscribed to a lot of communities, some of them don't seem to be updating. I know that my instance will only fetch new posts and comments from the communities I'm subscribed to, but even those are not being updated. Some communities seem to be working, but others just aren't updating. Is there a requirement that I'm not meeting to be able to fetch new data? Appreciate any ideas, thank you!