x value in magnetomeer calibration RTIMULib2 gives unbalanced values

I am trying to calibrate MPU9250 using RTIMULib2.

While calibrating the magnetometer for x axis the max value is nearly 1000 and the min stays at 35. the minima and maxima are of not of similar absolute value for the x axis. The calibration image is as below

at magnetometer — ImgBB

How do I fix this problem? Does this imply that there is a strong magnetic field nearby.

My magnetic calibration result is also attached herewith at magnetic-calibration-result — ImgBB

My latitude is 12degree north. height 960m above sea level.

I see that the compass magnitude in the main window after calibration is 460 uT while my android phone shows 41uT

The acceleration magnitude is nearly correct at 0.98

While calibrating the magnetometer for x axis the max value is nearly 1000 and the min stays at 35. the minima and maxima are of not of similar absolute value for the x axis.

After calibration, the min and max will be approximately centered and equal. Otherwise, the calibration was done incorrectly, was applied incorrectly, or the magnetometer was not calibrated in its final installation setting.

There are many situations that this simple-minded procedure cannot correct, such as this one. Follow the procedure in that post to fix such a situation.

Does this calibration procedure need to be repeated everytime the location of IMU is changed? I was thinking of moving to a completely open area to calibrate the IMU and then return to lab to use it.

I also saw a significant yaw drift of nearly 120 degrees over a period of an hour while the IMU was kept steady at a place after the calibration procedure which I had mentioned in my previous post.

Does this calibration procedure need to be repeated everytime the location of IMU is changed?

Often, but not always.

I also saw a significant yaw drift of nearly 120 degrees

Then the magnetometer was not properly calibrated, or there are varying magnetic fields in the region, or it is not being used at all by the code.

prior to runnig the RTIMUlib2 I had run the IMUMagCal and stored the results in the EEprom. Without doing the IMUMagcal step the RTIMULib was showing frozen results for the Magentometer values in the RTIMULIBGL main GUI.

Is it necessary to do the IMUMagcal as tediously as the magnetic calibration in RTIMUlib2. Or is IMUmagcal not at all necessary? Could it play a role in the wrong magnetometer calibration in RTIMUlib

I don't use RTIMUlib2. If IMUMagCal is not part of RTIMUlib2, there is no reason to expect it to work properly with RTIMUlib2.