Our magnetic poles are shifting quickly. I can imagine that being one of the causes if not THE cause.

"Since the 1990s, its movement has quadrupled in speed, to a current rate of between 50 and 60 kilometres (about 30 and 37 miles) a year. In late 2017, the pole's sprint brought it within 390 kilometres (240 miles) of the geographical north pole."

Article dated 15 MAY 2020 https://www.sciencealert.com/russia-is-stealing-magnetic-north-from-canada-and-this-could-be-what-s-behind-it

Our two poles are shifting quickly. I can imagine that being one of the causes if not THE cause.

"Since the 1990s, its movement has quadrupled in speed, to a current rate of between 50 and 60 kilometres (about 30 and 37 miles) a year. In late 2017, the pole's sprint brought it within 390 kilometres (240 miles) of the geographical north pole."

Article dated 15 MAY 2020 https://www.sciencealert.com/russia-is-stealing-magnetic-north-from-canada-and-this-could-be-what-s-behind-it