GPS compass errors

[Juggernaught]

Hi. So after my previous misfortune, my employer kindly replaced the drone, so back up and running again. All confidence now lost, I'm far more nervous and wary with the new Mavic. What doesn't help though is that the new drone often loses GPS signal in flight, and compass regularly doesn't calibrate - always complaining about magnetic interference. Previous drone I regularly did long flights (over 100km and 11hrs).This one I just don't trust to RTH with dodgy GPS, and it drifts slightly when one stops mid-air. Purchased through Aliexpress, all firmware and software up to date. Any thoughts or recommendations please? I'm in Durban, South Africa.

 

[Hollow Dog]

The drifting is consistent with compass error and or bad compass calibration.
Does it fly in a straight line when flying forward or does it drift to the side some when flying forward?

 

[Juggernaught]

To the naked eye it appears straight, I'll have to check and revert.

 

[BossBob]

Just wondered why you’ve been calibrating the compass?

 

[Hollow Dog]

Just wondered why you’ve been calibrating the compass?

BossBob asked this because the mavic has the processing power and software to determine if certain compass errors exist and will alert that calibration should be performed.
If you're NOT having problems, like drift, than the calibration if fine and is not needed or required and if done incorrectly could cause problems.

 

[Juggernaught]

I only calibrate in very new locations (like 500km away). But initially when it kept losing GPS, I would try and recalibrate.

 

[BossBob]

I only calibrate in very new locations (like 500km away). But initially when it kept losing GPS, I would try and recalibrate.

Never calibrated. Flew in SouthWest England one day. Drove to Western Scotland, about 400 miles north and flew the next. Stable, steady flight, no drifting, no yaw from centre line in straight flight.
GPS is completely different from compass and is more to do with the constellation of satellites and your drones ability to see enough of them to derive a good fix of position. I never fly without a steady connection to enough satellites. It took 10 minutes and a change of position last week but I was suffering from ‘canyoning’ due to being on a forest track between two stands of mature trees.