Sudden gyro measurement offset

I was recently getting ready for a flight when the aircraft (which was stationary on a table) started flying all over the screen and displaying EKF errors. I glanced through the logs and saw that the aircraft is fine for about 6 minutes and then suddenly shows very high NKF.SV/SP/SH/SM values for both IMUs. Looking a little further I noticed that both gyros show near zero values for the first six minutes and then the gyro for IMU2 suddenly shows an offset for X/Y/Z values. The accelerometer values don’t change at all which is very strange. Looking EVEN FURTHER I noticed that the GYRO HEALTH for IMU1 dropped to 0 at the same time that the gyro for IMU2 experienced the offset. Has anybody had something similar happen or have any idea what could cause this?

Post the log file, without it it is only guesswork.

Here’s the log file: It’s a little wonky because

  1. Sometimes when I convert a dataflash file to .log in mission planner some of the data gets clipped or flattened - this file is missing some GPS data but you can still see the gyro offset when it happens. It doesn’t happen to every file but it always happens to this one for some reason.
  2. I was flying near my house and don’t want that in a public forum so I zeroed all the gps and altitude data.

Reported as related so I’m adding a link here. No solution yet though.