After Cheklist and take off , the drone does not start the mission , ie stands in the same location ( waited about 3 minutes ) . Drone : DJ 3 Advance Device : Samsung Note 3
I had the same problem, try taking off before the checklist is done. I found if the drone is flying (hovering 1-2m above the ground) before the checklist is started it will work.
Hope this helps.
Drone : DJI P3 Advanced
Device : Samsung Galaxy Tab S2