I have been trying to complete the Una’s task Bleak Night Fog. I have taken the task, talked to the sailors and then completed the pirate ship three times and the task will not complete. I have a guild member that is having the same issue. I have abandoned and retaken the task after each time it failed to complete and redone the steps. I will try one more time.
Hey there,
I heard there was an issue where the Unas task will only complete on your first Ghost Ship of the week as the normal rewards are weekly content.
This is why players complete the Una once and then you can use auto complete tickets to skip the once a week barrier.
tyvm
But my guild mate had not done a ghost ship before.
Hmm then I have no idea! Maybe someone else will know 
Tyvm, your solution worked for me.