PC EU

Wondering if anyone else has encountered this. Today I unlocked Mirri's second quest (about her mother), I picked the quest up but didn't start doing it. Then I went into a dungeon with another player. I had Mirri and they had Bastion out but suddenly there was a quest marker over the other player's Bastion as if he had a quest to offer me, but obviously I couldn't talk to him. This only starting appearing after I got Mirri's quest and it only appears when Mirri is active, if I dismiss her the quest marker on Bastion disappears. Obviously, her quest is causing some sort of interference/bug with him.