There’s less of the funky shadow banning that Reddit does here, where your posts are rendered invisible to anyone but yourself without you knowing. I don’t think that can happen at all.

I'm pretty sure it can happen sometimes. If you try to post to a community you're banned in, you might still be able to hit "send", it will show up in your profile, and yet it won't be seen by anyone in that community. I've never bothered to figure out why this happens (and only sometimes), maybe there's also something funky going on with defederation between instances.