Never forget that the operating environment plays a huge role, and changes from minute to minute. My preferred flying environment in Cambridge could be counted on to be completely unpredictable.
Monitoring the WiFi environment with my laptop computer showed from 40 to 120 active wireless networks, with varying signal strengths. I was on top of a small hill and walking a few feet in any direction would cause the pattern to change. This describes only what was happening from the controller’t point of view. I have no idea what the drone was seeing.
3 different drones flown in this environment all had widely variable problems on different days, and the same day.
DJI is well aware of the problem, and has made a number of attempts to work around the problem - the basic WiFi, Lightbridge, and Ocusync. some work better than others, but all the methods are in the WiFi frequency range. Distances and multiple signals will always cause interference which will vary unpredictably. Thinking otherwise is a pipe dream, as it denies the physics of RD signals.