Using 11 years of magnetic field measurements from the European Space Agency's Swarm satellite constellation, scientists have discovered that the weak region in Earth's magnetic field over the South Atlantic—known as the South Atlantic Anomaly—has expanded by an area nearly half the size of continental Europe since 2014.
There have been periods of millions of years where the field hasn’t reversed, there have also been reversals within a few thousands of years.
The last reversal was 42.000 years ago, but it flipped back within a thousand years, so it doesn’t count as a full reversal.