Mavic Air Compass Error

G’day All, I have a new Mavic Air that seems to have a compass error - try as I might I can never get the compass icon (red pointer) to match the orientation of the drone, there is always a 15-20 degree error, very annoying.
I have been at great pains to ensure there is no magnetic interference around, taken off watch, emptied pockets etc but but nothing seems to work.
I have not been in touch with DJI yet, thought I would see if there was an easy fix from someone here first. Thanks for reading and hope someone has an explanation. Cheers!

Did you try using a different mobile device to rule the mobile device out as the cause of the issue?

I read in another forum a person with the same problem and DJI fixed it for him.