REMEMBER You must be able to have VISUAL contact with your drone. you must also be able to know the Drones orientation with the unaided eye... At 1 mile thats not possible.
Sure your drone will fly 3 to 4 miles out ....BUT not legally.
Basic rule of drone flying signal stability is to maintain a clear LOS (line of sight) for an unobstructed signal. If you can't see the drone with binoculars because something is in the way (not because it is too small to see), your signal is...
Without the recorded flight data, DJI or anyone else can't tell what caused your issue.
Did you supply the recorded flight data?
What drone company would you try next?
Trick question ... there's no other company providing drones that are even...
Then you'll get to pay $10000 in advance for an obstacle avoidance feature that's "coming soon", wait 10 years without it ever appearing, and be told that it'll actually need new hardware and not be anywhere as capable as what was advertised when...