Not seeing posts in subs from other instances--Where's the problem? - eviltoast

Basically what I said. This is the latest episode in the main speedbump I keep hitting with lemmy.

I’m trying to follow broadly when new TTRPG instances crop up. (DIYRPG.org is the latest I know of, and the one I’m currently having trouble with.) When I navigate to the communities from my ttrpg.network account, I can’t see any of the existing posts.

So is the problem on this end (ttrpg.network isn’t asking for the content) or their end (diyrpg.org isn’t sending the content)? And is there anything I can do about it?

If this can’t work smoothly, I’d at least like to know how it works.