Then I try the fedi icon and nothing happens at all… no expansion or anything. But I can see that the button is sensitive because it flashed as I clicked it. So then I forcefully copied that external link into a new tab in Tor Browser and it just shoots a blank.
Indeed. I can reproduce this behaviour with this comment from this thread. See the following screenshot from my network console. The body says {“error”: “not_logged_in”}, so maybe a caching error or something like that? I’ll ping the admin of lemmy.world