I was searching 'round the internet for instructions and guides to this. 90% of what I found were guides to fighting Horntail himself, not how to get the 3 knight badges inside the PQ for the quest to go straight to Horntail. Just to reiterate, I mean the PQ portion, not the fighting horntail part, I know that's bugged in some strange wacky way.
Do you need 6 people all there and present to enter? It seems a 6 person expedition with me by myself is not enough. I tried all the channels too. What am I missing here?