To top it off, it is proving hard to login to beehaw [probably the server is under stress] with the same details I use to login into Lemmy.one.
You can't login like that. You login on your home instance, your home instance is federated with beehaw and so has a "window" into all its content, but you are still grabbing it via your home instance. Put the url if the instance you want to join into your home instance search bar and the community will show up and you can subscribe through there. Same content but different url.