“Could it be changes in the magnetic field?”
Not just in the earth’s magnetic field, but also in the sun’s fields. I read recently on the Canadian Geophysics site (they monitor the earth’s magnetic field strength and the North Pole movement) that the movement of the North Pole across Canada now has an 85 kilometer daily circular wobble. Kind of like a top wobbles before it goes totally out of balance.
If you get more information on this please keep us posted. Thank you
Usually, it makes a complete 'roll'.
Evidence in the magnetic fields in ancient rocks confirm that it has happened before, and more than once.