¿Por qué los hilos de Discourse supuestamente federados por ActivityPub son inaccesibles desde clientes AP externos?

[RokeJulianLockhart1 (Mr. Beedell, Roke Julian Lockhart)]

What the heck has occurred here? I have never written like the undermentioned:

RokeJulianLockhart:

Discuss this on our forum.

...and someone's taken a sledgehammer to my markup.