OK so I must be really dumb. I had a red alert come up and joined it, selected the mission, and the I found myself back in sector space having never seen a Borg. What did I do wrong / what should I have done? The mission still shows up as needing to be completed.
Same thing happened to me..clicked on the red alert..took me to the Borg Front, selected the mission, even received the 5x XP bonus item, then it dropped me into sector space again. Hopefully they will fix it with the patch this morning!