Basically: yes the dropdown menu appears, just as for usernames, but if you choose the item from the dropdown that you see, the Lemmy UI will do the wrong thing. My first link was made using the dropdown, while my second ignored the dropdown and just used the exclamation mark. Notice how my first link takes you to an entirely different instance? But the second link goes to the version of that community while keeping you on your same instance.

Jumping in, but I’m very curious about this. I’ve never seen the dropdown menu not create “!community@instance.org” links.

I am now taking my discussion.online alt to see, and with !newtolemmy@lemmy.ca, created from the dropdown, the link works as expected.

How do you manage to get harcoded links from the dropdown?