It’s because the roots are too close to the surface. Children will add particles around the general area of it’s parents. With the roots being on the surface, it’s going to have some children spawn offset from that, and appear floating.
Generally speaking, you want your root particles to be inside your geometry, and pointing inwards. This is normally done by default anyway, but it looks like you’ve turned off the setting which keeps the root in place.
Try selecting the root verts for the hair, and moving them downwards and that should fix it. Make sure Preserve Root Position is ticked, to make sure that they stay where they are put.