I started over with a new Titan shortly before TTK release. I received the Path of the Striker subclass quest line from Zavala. Somehow the quest line progressed past step 6 (complete the path) without me having to max out the striker subclass. I completed the Path of the striker and received the reward. I also completed The Sunbreakers' Challenge quest line and received that reward. Now I am completely unable to make the Path of the Defender quest line appear. Nothing I do in terms of going into orbit, changing subclasses or reloading areas ever makes it appear on Zavala. I can only assume the quest is bugged for me and would appreciate any advice towards getting it fixed.