As you can see in the screenshot, the line where it would normally say "Help a team in [previous quest world] or [current quest world] using the team up kiosk" is blank. Not only is it blank, it is entirely non-functional; Helping teams in both my current and previous questing worlds (Polaris and Khrysalis for the wizard in question) did not complete the task or award points. It's frustrating and demoralizing.
This happened in the Spiral Showcase event last week, and has continued on in the Spiral Scene event this week.
This is only happening on one of my wizards. I suspect it is somehow related to the "Raid Island" quest. I cannot definitively prove this, but I do know that this task in weekly events was functional before I completed the Charnel House instance and received the Raid Island quest, and it broke sometime after. If the quest is indeed somehow related to the bug, perhaps the guild quest has left the game confused as to what world my wizard is currently questing on.