Here's some follow-up that I've been working on to show how DJI's "GPS Altitude" is derived from atmospheric pressure and can vary with the weather by +/-200 metres.
For some months, I ran some test flights with a Mavic 3 pro from a known...
I've been able to avoid the problem with ferrous materials by holding the drone waist high when I power it up. The usual launch location on my patio creates a problem, presumably because of rebar, but I'm able to stand in the same place and start...
Best: Being able to capture dramatic photos from an aerial perspective.
Worst: People's complaints about reasonable limitations imposed upon their use of drones. Just because someone invents a new gadget doesn't mean that folks who buy one...
If I thought DJI would address it with a FW update, that would be good but they can't answer that question when I asked them. Another disappointment is the battery life. I'm not getting anywhere near what I get with my M4 Pro, same standard battery.