So far I had a couple of flights, outdoors it mostly went fine (except for 1 time when the drone started drifting without me doing anything, and gps signal got lost.)
Indoors it also started drifting without any input, so I just dont try anything indoors anymore.

Compass & Remote are calibrated.
Today I took a small testing flight in a garden, and looked at the sensors log, and it seems quite concerning.

Anyone has an idea whats going on here?
http://healthydrones.com/main?sh ... d=SENSORSSignal_Map

Looking at those logs, you have very bad signal, very low sat count, this is what is causing your AC to drift in and out of Atti mode.
Don't know why you calibrated your compass, but you have, but where did you calibrate your compass is most important.
Also you are going to find it difficult to get enough gps signal flying around at 7 meters surrounded by trees and houses.
If your Mavic is loosing gps signal fly it up higher you will see it gain more signal and flying much more steadily.

Weirdly enough, if I look - for example on a GPS app on my phone, the GPS is fine and has plenty of satellites all the time.  I callibrated the compass indoors, I think that could have been the problem.  Will format the card, and recalibrate everything outside, and see if I get different results. Keep you posted.

I read so many people that expect it NEVER to drift. It is a quad, no GPS = 100% drift. You just need to deal with it. What we don't have to deal with, is loss of GPS without reason, that seems to happen to many people. I hope this will improve by firmware. It's like a service "reboots" in the mavic as it comes back...

you do not calibrate the compass indoors. calibrate it in an open area outside. also if you fly at different spots that a far away from one another calibrate compass again for each flying spot.

Nees Posted at 2017-2-17 04:29
I read so many people that expect it NEVER to drift. It is a quad, no GPS = 100% drift. You just need to deal with it. What we don't have to deal with, is loss of GPS without reason, that seems to happen to many people. I hope this will improve by firmware. It's like a service "reboots" in the mavic as it comes back...

By the way, at 54feet the drone was just hovering (it was taking a panorama using litchi app). GPS signal suddenly was lost (after 6minutes of hovering) despite clear sight and no obstructions in all directions (the houses around are all around 50-65 feet high.

Blackline Posted at 2017-2-17 05:37
you do not calibrate the compass indoors. calibrate it in an open area outside. also if you fly at different spots that a far away from one another calibrate compass again for each flying spot.

Just noted that the remote signal data is even more worrying than the GPS data. (first link) Shouldnt that be independent from calibration?

GPS Signals are not fixed !  the serviceable Satellites come and go,   apps are available to see this and even predict how many are viewable at a given time in that location, along with Kp etc ( different from serviceable)   also as OP said dont calibrate your craft indoors,  its worth going back through your manual just to ensure you are operating it as suggested,  even poorly aligned antenna can loose RC ,  and a poorly calibrated craft  will return with poor performance every single flight.   hope that helps.