I’ve read that it should be possible, but my experience seems to show that that is incorrect, that you need a login for every instance where you wish to make a post or comment. Could someone who knows clarify this?
If you need a login for every instance of Lemmy to participate in non-local communities, then that will, I think, be the #1 issue with Lemmy adoption, and the main reason folks bounce off.
I am able to see other communities, but not comment on posts in them without a login for that instance, in my experience. Is that supposed to be the case?
You have to find the same community in your home instance, instead of going to that instance directly.
I agree this is confusing, especially if you come there from a link. There’s no easy “go to this community on my instance” link right now, though there are user scripts to make this easier.
What you can do is copy a link to a community or post and paste it in the search on your home instance. That’ll hopefully show that post and allow you to subscribe.
Try to use https://greasyfork.org/en/scripts/469273-lemmy-universal-link-switcher
It would make it easier to just always go to your instance!
I’ve been able to post on multiple communities in multiple instances with a single account in one instance. I wonder if you’re running into the issue where some major instances have defederated from each other. Which instances have you tried to post to from your lemmy.ml account?