Official comment

Missing pictures happens when you are using Active Connect mode and the RC signal strength drops below about 85%. Make sure you are maintaining a strong signal by pointing your antenna appropriately and tracking your aircraft using the directional indicators.
If it is not possible to maintain a strong signal due to interference or obstructions, you can use the Connectionless mapping mode which relies on a distance based trigger that is local to the aircraft instead of the trigger from the mobile device.
https://support.dronesmadeeasy.com/hc/en-us/articles/217006946-Connectionless-Mapping
The horizon issue is likely the C1 or C2 button being pushed by accident.