I was having this same problem. I had returned to the Jungle, multiple times, and gained experience, mastery points, hero points, etc. Unlocked my glider and even went on to get updraft gliding last week, and it still wasn’t activating the “Establishing a Foothold”. I think I might have had my Central Tyria story activated at the time, not the HoT story, so it never registered.
I tried all the things recommended in the forums: quit the chapter, start again; quit the chapter, waypoint away to another map, reactivate the chapter; quit the chapter, start and end another chapter in another story (I’m working on Season Two now), then switch back to HoT; quit the chapter, waypoint away, activate the chapter, then walk back into HoT area. None of it worked. I finally tried one more thing: quit the chapter, rerun chapter 2 “Torn from the Sky” completely — and it looks like it worked! The scout in chapter 3 acknowledged that I had a glider and I’m finally progressing forward.