edit: cut most out, mystery solved-ish.
As a side note, rather annoyed that gmail stuffed the email about XXI into spam so I never saw it.. not anyones fault at llamalan obviously, just annoying as it appears to already be fully booked!
Ah, it's specifically if click onto the banner onto XX, which then shows XX, but still leaves the side panel for XXI showing. And as I hadn't realised what status of XXI was, I didn't spot there was a new event.
And I guess situation has never been where next pan after current was already bookable before lan so it wasn't designed to gracefully deal with not showing top event's side panel if click on banner.
And I assume this have something to do with the llamalan 21 forum showing up, and noticed when get back to the info page, it has a signup for llamalan 21 link at top, so presumably site is somehow mixing up two events together?