I notice the link you posted. You use !entertainment but the URI is different, looks like a traditional webpage link: https://beehaw.org/c/entertainment. When I click on it in Jerboa, it opens the browser and it looks like beehaw.org is down (hug of death?).
What software currently recognizes !entertainment ? I guess Jerboa doesn't handle this type of link yet or is jumping to another instance beyond the scope of federation of an app like Jerboa?