Terrain Follow - Arducopter

Hi; I’m posting this to see if somebody can shed some lights.
Yesterday I flew a mission that was supposed to be in “Terrain Follow” mode, however it turned out to be in Relative altitude.
When planning the mission at home and just before the flight I double checked in the ‘status’ tab that the “terrain tiles” were loaded with none pending - one strange thing I noticed is when reading the mission form the Pixhawk (as a double check before arming) the Altitude drop down menu (Absolute-Relative-Terrain) in MP Flight Plan window was not there at all.
Other thing: the planned images in the Flight Plan were 87, whereas the actual CAM_TRIGG messages were 82.
Below you can find the link to the Pixhawk logs and the planned way-point file:
Just to give some basic specs, the UAV is a multirotor (copter), FC is a genuine 3DR Pixhawk (FW AC3.5.0), ground station running latest stable Mission Planner 1.3.49.
If something else is needed just let me knw.
Thanks in advance.