Confirming that we implemented fixes for this earlier. The issue was:
The event that takes place during "A Firm Response" would become stuck and Windshaper Skyborne on Zephras Isle could not proceed. You'd walk up to talk to Belathaan Brightwish near the Shrine of Akir on Zephras to start the event and it would then lock up and stall after Lorthuna Spawned.
We attempted a fix a couple of days ago, but it didn't work. Today's fix looks like it worked, and we're seeing testers complete the quest.