I subscribed to communities, but my Lemmy instance receives only a few posts, comments and votes. I can see linked instances, but whether or not they sync data feels hit or miss. I’m not quite sure if this is expected. Does Lemmy have a utility similar to the Matrix federation tester?
Actually looking at their instance… They’re using Cloudflare (I see the email protection injected code). Cloudflare in particular likes to mark ActivityPub traffic as “bot” traffic and block it. It’s more likely that lemmy.ml is blocked for that particular instance by cloudflare. Smaller instances like mine probably don’t get flagged. So it shows up in their instance just fine… https://lemmy.haigner.me/post/8?scrollToComments=true
But other instances might have problems talking to them. They need to setup a page rule to allow lemmy traffic through cloudflares bot detection.