[2D] Rigid body snaps through floor and back

Hey, I'm having a small problem with rigid bodies in 2D space.

I have a player character (platformer) in 2D, and every time he reaches the floor again after a jump, the character falls slightly below the floor but then snaps back up. There's no mechanical problem, i.e. the game is still playable without issues, but it's an aesthetic problem, because it looks sloppy.

Has anyone had experience with this kind of thing?

The settings of the rb2d are:

 Mass 5
 Linear Drag 1
 Angular Drag 0.05
 Gravity Scale 4
 Interpolate: Extrapolate (also tested with the other settings)
 Sleeping Mode: Start Awake
 Collision Detection: Discrete (also tested with continuous)
 Freeze Rotation: Z

Any help would be appreciated.