I just noticed Zim changed the signal. 5 & 6 didn't used to be there. So all 6 are green and the signal is still there? #6 should be the meeting with Sheila and Maeve and should give you a new signal.
No worries. It should have worked first time anyway. When Zim reads this he may take a look, you might have found an odd bug, or got unlucky with renpy deciding to not mark quests as complete, which does happen.
