Why is torque sometimes reported in kg m, instead of the usual N m?

Those other sources were probably referring to kilogram-force instead of Newtons. Given the constant conversion between mass and weight on Earth (i.e., $g = 9.8\,\textrm{m/s}^2$), mass and weight units are often used interchangeably in non-scientific contexts. So, torque can be expressed in kgf-m, where 1 kgf is the weight of 1 kg on Earth's surface. Notice that this is a multiplication, not a division. Units of kgf/m would be completely incorrect.

The non SI unit is often written as 1 kg-m and is equal to 9.8 N m.

In such a case the 1 kg refers to the unit 1 kg force which is the weight of one kilogram.

Another unit is the Imperial (and US) unit the pound-foot which is equal to approximately 1.36 N m.
Here the unit of force is the pound force.