I have been reading the post again.
First off I had similar error on a mission the camera just went limp and just pointed strait down.
When flying a mission with curved turns the drone never gets to the waypoint so it can't pick up any new Instructions / Actions 'Stay For' 'Start / Stop Recording etc. The Gimbal pitch is controlled constantly from your controller if it loses contact the camera will point to the ground.
Looking at your mission settings you are using 'Straight Lines' but looking at your WP's they all have curves and WP 2 has 187ft curve, a Straight Line mission has Curve size of 1ft. Perhaps at PW 2 it is getting confused with the curve on a straight line mission, but I am only guessing. Have you tried moving WP 2 say 200ft closer to WP3 just past the point where the mission is stopping if there is some interference around that area.