Recently I've started having issues with yaw drift on my Mavic. Regardless of the height, wind, or situation if I don't move any of the controls the mavic swivels the left slowly. Not only does this make filming steady shots next to impossible but it also affects the flying. I can counteract this in most senarios however when symmetry and lines are part of the scene it is very frustrating. Yesterday I was flying over corn fields in the same direction as the crop lines. I couldn't keep the mavic flying perfectly straight forward due to the yaw drift, and it completely messed up the shot on every attempt. I have recalibrate the IMU and compass on numberous occasions and in ideal settings. I have also reset the drone and have all the firmware up-to-date. This issue seems to have arisen spontaneously 2-3 months ago. I am concerned it is related to the compass, but every time I check the compass it shows no interference and seems to be fine. I have also been flying in may locations/states/countries so I don't think it is location specific. Has anyone else been experiencing this? Has anyone found a fix for it? Some forums I've read people have mentioned sending the drone in for evaluation just to get it back 4 wks later with the response that nothing could be found and the issue persists. I'd rather avoid this if possible. Any help or advice would be appreciated!

Did you calibrate the remote's sticks? I had that some time ago, and going into the RC stick calibration solved that issue.

Yep, I have had the same issue with both my Mavic & P4P.  I did a "cold" IMU calibration and it fixed the issue.  Flying perfectly now.

Someone else had the same problem recently. Turned out to be stuck calibration.

Can you physically see it yawing or is it just on the screen?  It *could* be the gimbal as opposed to the flight controls.  You can try turning off the synchronise option in the gimbal options to see if that helps.

Other than that, are the props all good, not dented in the slightest?  Ive got one with a tiny indentation in the middle.  When that prop was port side the vehicle yawed left.  I moved it to starboard and now it yaws right (really slowly).

As Proquad mentioned,COLD IMU to the rescue!

Please try to calibrate the RC. Here is the tutorial video for reference.
If RC calibration is successful and the issue remains, you can refer Proquad's suggestion to do cold IMU calibration again.