Oval / Disk / Flat Instead on Sphere while calibrating

[AsternA]

Hey Paul,
I have been using MotionCal.exe to calibrate my boards which have an ICM - 20948 IMU with an nrf52840 chip.
Most of the calibration process works perfectly.
Recently, while trying to calibrate 2 more units, the shape that shows up on motion cal is as far away from a sphere as it can be. I have seen flat circles, oval shapes, and even an American Football shape.
I am wondering if you know how or why this is occurring, and how I can fix it. Because of these results, I cannot calibrate my units and therefore am seeing unpredicted results when I use my products.
Any help is appreciated!
Will take snapshots and upload them here to show you what I mean.
Thanks
Almog

[PaulStoffregen]

MotionCal exists because those terrible results are easy for human eyes to recognize, not so simple to detect well only with software. Usually they happen because of externally applied magnetic fields. But with unproven hardware, pretty much anything is possible. Really can't help diagnose unknown hardware!