I too have the same issue. I upgraded the firmware, re calibrated the sensors and after taking off whilst hovering the Mavic is just moving up and down left and right.
on .500 it was rock still.
I have been reading that .400 is the best firmware still. Never flew on that version so not sure?
Should I roll back to 400. seems 550 has issues?
I also have another issue.
I was trying to take a shot at night. and it was set to autofocus. I got one good shot. then I wanted to experiment with the iso settings and shutter speeds to take multiple shots and see differences. After I switched to Manual Focus, no matter what I did I couldn't get it to go back into focus. Even If I switched back to auto it wasn't focusing.
Seems like there is an issue with the new firmware and the app settings/focus control ? I'm not sure.
Eager to see what others have to say.
Cheers