How do I get nice look shadows that don't flicker?

For some reason the shadows in my scenes flicker and don’t appear stable. I have messed with all the settings in the quality menu but nothing fixes the issue. I can sometimes make shadows closer to the camera appear stable but then shadows further away look bad. The game is a 3D side scroller so my camera is fixed in place, my backgrounds are what is moving in the scene. My scenes are lit with one main directional light which is responsible for the shadows then fill + rim lights that don’t cast shadows.

Hard to tell what the issue is without a video.

Have you played with the bias settings on the light?

See here for more info: