I've been in the cockpit of a medium-sized propjet at 2500 feet looking for 4 other planes in the vicinity of the same airport we were wanting to land at and with 3 pairs of eyes and knowing where the planes were, it was still very hard to see...
The flight data would show exactly what caused the issue, but the OP doesn't seem interested enough to find out.
It's puzzling why someone would ask for help and then lose interest.
You have picked up some odd ideas that are confusing you.
The DJI Fly app works anywhere in the world without any workaround needed.
I don't think you have understood what people have been saying.
The Mavic 4 pro only works with the RC2 or RC2...