DJI stated in their upgrade note that one benefit of the update was  'Improved encryption to enhance security during transmission.' I suspect that the frequency hopping algorithm in the last version was messed up.  
With FW 1.7.0.90, I flew in an area with no cell or WiFi signal;  the craft was 2m in front of me and video signal could disappear (control signal was lost once at a greater distance and that triggered a RTH). Typically the problem would resolve after few minutes in the air but flying was highly unsatisfactory under such conditions.

The nasty thing is that the problem was intermittent.

Time will tell whether the present update is a full fix but given that DJI expressly stated it was to address signal loss issues, we can hope.

DJI stated in their upgrade note that one benefit of the update was  'Improved encryption to enhance security during transmission.' I suspect that the frequency hopping algorithm in the last version was messed up.  
With FW 1.7.0.90, I flew in an area with no cell or WiFi signal;  the craft was 2m in front of me and video signal could disappear (control signal was lost once at a greater distance and that triggered a RTH). Typically the problem would resolve after few minutes in the air but flying was highly unsatisfactory under such conditions.

The nasty thing is that the problem was intermittent.

Time will tell whether the present update is a full fix but given that DJI expressly stated it was to address signal loss issues, we can hope.