I have had an issue with my mavic pro lately, when It hovers it seems to drift slightly, the moment is only just visible on the display screen as it is that minimal however when I try to do a 360 or a pano it is really noticeable as the pictures stitches together horribly! And is unusable.
There has been 2 occasions I have tried panos and on both It was a calm day so exces wind wouldn’t be a factor, 2 separate locations so magnetic interference should be ruled out.
I did change a ribbon cable in the gimbal recently however I can’t see how this would have made any impact on its flying capabilities.
Do the imu at home no need for gps lock its easy to do it tells you step by step what positions to put the drone in for calibration and like someone said make sure its a flat surface. If you look in the settings on your device your current calibration will be shown with green indicators and you will probably see 1 or 2 not sitting level. Good luck