I have also logged this on the support page, but I am sure that I am not the only one experiencing this issue considering the mess that this event has been in.
Following on from the previous issues for the World Cup Event where the Practice Match quest tied itself in knots. Now the First Group Stage Match quest, that I played and won on Tuesday, is still showing on my quest list as incomplete. Please give it a nudge.
Come on guys, pull it together.