Here is a repost of one of my detailed explanations from above:
"I'm aware of the connection requirement for automated gimbal control. This behavior as documented does not match my scenario.
1) I never got a disconnected message as you see on the screen recording and mission logs. I only got a very brief signal drop to 8% and it shot back up to solid signal.
2) even if we want to call that a disconnect it was very short lived. Very. A s cond or two. The AC and RC were solidly in connection for the remaining waypoints for which gimbal control is ignored."
I have flown about about twenty Litchi waypoint missions on a course that I have been using to characterize Litchi, but I use the Android version, which operates somewhat differently than the ios version. In any case, my course runs about the same shape and length and treed environment as yours. There are two spots where I dip down below the tree line over two separate ponds in my neighborhood, which often causes a very degraded signal while over the first pond, and a complete signal loss over the second pond. Very good for tests.
I often see a link with zero bars (ios shows a link quality number, as well as bars, but android shows bars only). My missions often show zero bars for long stretches, with no apparent problems, continuing through waypoints, but with poor video, (I don't think the signal indicators are very well calibrated to true signal strength). At some point, I run out of control signal completely, and then I get a "Signal Lost" voice message, plus a red display message display that says "Disconnected" "Signal Lost".
I have never heard the "Mission Ended" message, even with a complete signal loss. Instead, I just hear "Signal Lost". When I hear the "Signal Lost" message, the AC will continue to fly the rest of the mission normally but eventually it will reconnect automatically. It won't control the gimbal, nor change speeds between waypoints while it is disconnected. However, it will never resume control. Once it loses connection, all the smooth interpolation of speeds and gimbal pitch not only stop, but they remain frozen for the rest of mission, at whatever pitch and speed that existed just before the disconnect, whether you regain a good signal or not.
I wonder if your "Mission Ended" voice message in ios is essentially the same as "Signal Lost" in the android version, because the behavior you described matches the same behavior I observe with "Signal Lost". I know you said you only had degraded signal for a brief time down to 8%, BUT, I doubt that displayed signal indicator is really accurate and updated frequently enough, especially under poor signal conditions. I'm not certain you can rely on that number to be sure you didn't lose link. But if you did lose link, there should have been a notification other than "mission ended". I would think.
Hope that helps.
EDIT: I found a configuration that does indeed allow Litchi to resume control of speed and gimbal after a signal reconnect. See my Feb 8 2016 post below.