Strange normal map behaviour

When applying a normal map to one part of my model the shadows become incredibly sharp and seams become visible. Settings are identical to another model which works fine.

It also doesn’t seem to be related to the map itself as applying the normal map of another model gives the same issue. Normal map was made in Substance painter.

The model: Note how the colour is much darker and undetailed and the clear seam around the ear.
The nodes: All standard things should be in place.