Where does the magnetism in neutron stars come from, as neutrons are neutral particles?

Artist’s concept of a neutron star. NASA/Dana Berry

No one knows the exact origin of neutron-star magnetism. The fact that these exotic objects have neutron
in their name should not be cause for concern. While neutrons are
charge-neutral particles — meaning magnetic fields don’t alter their
motions — neutron stars are not made exclusively of these particles.