Can't start PVP as someone is in a quest

Hi

I'm late the party with AOEO but absolutely love it. The problem is when I play with upto 4 friends we often get the message one person is in a quest and we can't start the PVP match. No matter how hard that person looks through the menu/map open quests it appears they are not actually in a quest.

It's really quite annoying as we fiddle around looking for the quest to complete but are unable to find it so have to give up on the multiplayer.

Is this a known bug or am I missing something obvious

Thanks