Will give you one easy tip that without a doubt will reveal if you had a yaw error due to
powering on your drone in close vicinity to something magnetic on that balcony you started your flight from ...
I imagine that you by now have tried to upload your flight log to
Phantom Help Log Viewer ... if not, do so.
If you there look at the drone icon ... the red "arrow". If that icon there at take off, points in another direction than your drone actually was pointing ... you had a yaw error & that would have been the reason for your incident.
Below one of my own flights uploaded to PhantomHelp ... The red arrow is pointing in approx a south westerly direction, into the road bend seen there when it was ready for take off ... my drone did that in reality also, so all was OK as my drones IMU info about the pointing direction agreed with reality.
View attachment 140381
This check you can & should do before every take off ... check your drone icon's pointing direction on the map view in the Fly app instead ... if it agrees with reality all is good, if not ... power down your drone & move to another spot & repeat. And remember ... a yaw error is created when the drone is powered on (not at take off) when the compass is magnetically deflected.