Help! Dji app controller symbol no bars after takeoff

[wayneiak]

Did two flights today in which both lost signal on my phone using dji app, the screen just judders and I see the green bar top left flicker red then the controller bars drop to zero, the rc as full bars and the drone flys perfect I'll attach videos any advice/help would be much appreciated.

 

[wayneiak]

Sent from my SM-T700 using MavicPilots mobile app

 

[wayneiak]

Sent from my SM-T700 using MavicPilots mobile app

 

[wayneiak]

Sent from my SM-T700 using MavicPilots mobile app

 

[wayneiak]

Sent from my SM-T700 using MavicPilots mobile app